1,3,4-Thiadiazole-2-carboxylic acid derivatives, process for making the same and fungicidal and nematocidal compositions containing same

ABSTRACT

1,3,4-thiadiazole-2-carboxylic acid derivatives of the formula ##STR1## wherein R is C 1  -C 6  -alkyl, C 2  -C 6  -alkenyl, C 2  -C 6  -alkinyl or C 3  -C 6  -cycloalkyl, 
     R 1  is C 1  -C 6  -alkoxycarbonyl, aminocarbonyl, C 1  -C 8  -alkylaminocarbonyl, C 3  -C 6  -cycloalkylaminocarbonyl, di-C 1  -C 8  alkylaminocarbonyl, cyclohexylmethylaminocarbonyl, alkoxyalkylaminocarbonyl, morpholinocarbonyl, pyrrolidinocarbonyl, piperidinocarbonyl or cyano, 
     and n is 0.1 or 2. 
     The compounds wherein n is 1 or 2 have both a high fungicidal and nematocidal activity. The compounds in which n is 0 are the starting products or intermediate products in making the compound in which a sulfonyl or sulfinyl group is present (n=1 or 2) but have also nematocidal properties of their own. All compounds of the invention avoid the undesirable environmental properties and other shortcomings of the prior art products, particularly those of the broadly used mercury compounds.

BACKGROUND OF THE INVENTION

The invention relates to 1,3,4-thiadiazole-2-carboxylic acid derivatives.

Compounds for use against phytopathogenic fungi are already known. Compounds in use of this kind are for instance manganeseethylene-bisdithiocarbamate (U.S. Pat. No. 2,504,404), N-trichloromethylmercaptotetrahydro-phthalimide and N-trichloromethylmercapto-phthalimide (U.S. Pat. No. 2,553,770, U.S. Pat. No. 2,553,771, U.S. Pat. No. 2,553,776), tetrachloroisophthalodinitrile (U.S. Pat. No. 3,290,353, U.S. Pat. No. 3,331,735) as well as mercury-organic compositions.

Agents for simultaneous use against nematodes and pathogenic soil fungi are likewise known, for instance sodium N-methyldithiocarbamate (British Pat. No. 789,690).

The object of the present invention is to provide agents of superior activity or other superior properties which have simultaneously fungicidal and nematocidal effects.

ESSENCE OF THE INVENTION

The compounds of the invention have the formula ##STR2## wherein R is C₁ -C₆ -alkyl, C₂ -C₆ -alkenyl, C₂ -C₆ -alkinyl or C₃ -C₆ -cycloalkyl,

R₁ is C₁ -C₆ -alkoxycarbonyl, aminocarbonyl, C₁ -C₈ -alkylaminocarbonyl, C₃ -C₆ -cycloalkylaminocarbonyl, di-C₁ -C₈ -alkylaminocarbonyl, cyclohexylmethylaminocarbonyl, alkoxyalkylaminocarbonyl, morpholinocarbonyl, pyrrolidinocarbonyl, piperidinocarbonyl or cyano and

n is 0, 1 or 2.

The compounds of the invention wherein n is 1 or 2 have a surprisingly broad spectrum of activity against phytopathogenic fungi, superior to prior art agents of the type above listed. They also have a good compatibility with agricultural plants and an adequate duration of their activity. They have furthermore the advantage that they are also effective against nematodes in which case they can be used, contrary to the prior art nematocidal compounds, without a waiting time between their use and the planting period because of their high plant compatibility. Thus, they permit a problem-free action against pests. A further advantage is that compared to the toxicologically objectionable mercury compounds they are environmentally acceptable.

Due to these properties the compounds of the invention can be used both in agricultural operations and in horticulture for treatment of the soil or for application to the leaves, etc.

The compounds of the invention wherein n is 1 or 2 have a superior activity against a large number of noxious fungi such as for instance Pythium ultimum, Penicillium digitatum, Botrytis cinerea, Alternaria solani, Fusarium avenaceum, Tilletia caries, Helminthosporium gramineum, Ustilago avenae, Piricularia oryzae and others.

The nematocidal activity is also effective against many genera of nematodes, for instance Meloidogyne sp., Rotylenchus, Pratylenchus, Tylenchorhynchus and others.

In the above formula I, R should preferably be methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec.-butyl, tert.-butyl, pentyl, isopentyl, neopentyl, hexyl, isohexyl, 2-propenyl, 2-propinyl, cyclopropyl and cyclohexyl.

R₁ preferably should be methoxycarbonyl, ethoxycarbonyl, aminocarbonyl, methylaminocarbonyl, butylaminocarbonyl, dimethylaminocarbonyl, cyclopropylaminocarbonyl, propylaminocarbonyl, isopropylaminocarbonyl, (N-butyl-N-methyl)-aminocarbonyl, (2-methoxyethyl)-aminocarbonyl, (3-methoxypropyl)-aminocarbonyl and cyano.

The compounds of the invention can either be used individually or intermixed with each other or intermixed with other active agents. If desired, other fungicidal, nematocidal or insecticidal compounds or other pesticides may be used depending on the specific purpose.

The compounds may be used in the form of compositions such as powders, dusting agents, granulates, solutions, emulsions or suspensions. There should then be added liquid and/or solid carrier materials or diluents and if desired surface active agents.

Suitable liquid carrier materials are water, mineral oils, or other organic solvents such as xylene, chlorobenzene, cyclohexanol, dioxane, acetonitrile, acetic ester, dimethylformamide, isophoron and dimethylsulfoxide.

As solid carrier materials there may be used lime, kaolin, chalk, talc, attaclay and other clays as well as natural or synthetic silicic acid.

If surface active agents are added they may for instance be salts of lignosulfonic acids, salts of alkylated benzoesulfonic acids, sulfonic acid amides and their salts, polyethoxyamines and alcohols.

If the agents are used for seed treatment there may be added dyestuffs in order to give the treated seed material a distinct coloration.

The fraction of the active agent or agents can be varied within a broad range. The particular concentration of the agents depends mainly on the amount of agent actually employed. For instance the total compositions may contain about 1 to 95% by weight, preferably 20 to 50% by weight, of active agent or agents and about 99 to 5% by weight of liquid or solid carrier materials. Part of the carrier materials may be replaced by up to 20% by weight of surface active agents.

The compositions may be applied in conventional form, for instance by spraying, dusting, fogging, gasifying, smoke formation, spreading, pouring or otherwise.

PROCESS OF MAKING THE PREFERRED COMPOUNDS (n=1 or 2)

The compounds of the invention wherein n is 1 or 2 can be formed in various ways.

(A) Compounds of the formula ##STR3## in which R and R₁ have the same meaning as in the above formula I and n is 0, are treated with oxidizing agents, preferably organic hydroperoxides, per-acids or inorganic oxidizing agents, in equimolar amounts dissolved in an inert solvent.

(B) Compounds of the invention wherein R₁ is a carboxylic acid amide residue can be made by reacting the compounds of the above formula II wherein, however, R₁ is C₁ -C₆ -alkoxycarbonyl with a suitable amine followed by treatment with an oxidizing agent as under A.

(C) If the compounds of formula I are intended to be of the type wherein R₁ is cyano they can be made by treating compounds of the above formula II wherein R₁ is aminocarbonyl with a dehydration agent followed by treatment with an oxidizing agent as described above at A.

(D) If the compounds of the invention are intended to be of the type wherein R₁ is a carboxylamide residue they can be made by reacting compounds of the formula

    R.sub.1 "--CO--NH--NH.sub.2,

wherein R₁ " constitutes a carboxylic amide residue as listed with carbondisulfide in the presence of a base so as to form a compound of the formula

    R.sub.1 "--CO--NH--NH--CS--S.sup.(-) Me.sup.(+).

The latter product is then reacted with an alkylating agent to form a compound of the formula

    R.sub.1 "--CO--NH--NH--CS--S--R

whereupon it is treated with a dehydration agent and an oxidizing agent in order to obtain the desired compounds of the invention.

(E) If compounds are wanted of the type of formula I in which R₁ is a carboxylic acid residue, the proceeding could be as follows: a compound of the formula

    H.sub.2 N--NH--CS--S.sup.(-) Me.sup.(+)

is reacted with an alkylating agent to form a compound of the formula

    H.sub.2 N--NH--CS--S--R.

The latter reaction product is then treated with a compound of the formula

    R.sub.1 --CO--CO--Cl

in which R₁ is C₁ -C₆ -alkoxycarbonyl so as to form a carboxylic acid derivative of the above formula II, the reaction being carried out under dehydrating conditions. The last obtained reaction product is then treated with an oxidizing agent as stated above at A.

In all these compounds R and R₁ have the meaning as in Formula I except as stated and Me.sup.(+) is a cation of an organic or inorganic base.

II. PROCESS FOR MAKING THE COMPOUNDS USED AS STARTING PRODUCTS BUT ALSO AS FINAL PRODUCTS (n=0)

The compounds of the formula I wherein n is 0 and which have not been disclosed heretofore can be made as follows:

Compounds of the formula

    R.sub.1 '--CO--NH--NH.sub.2

in which R₁ ' is C₁ -C₆ -alkoxycarbonyl are reacted with carbon disulfide in the presence of a base so as to form a compound of the formula

    R.sub.1 '--CO--NH--NH--CS--S.sup.(-) Me.sup.(+).

The latter reaction product is then reacted with a dehydration agent so as to form a compound of the formula ##STR4## The latter compounds are subjected to the action of an alkylating agent, if desired in the presence of a base. There are thus formed the desired compounds of the formula ##STR5## The latter may be further reacted with suitable amines to form compounds of the formula ##STR6## In all of these formulas R and R₁ have the meaning as in formula I unless otherwise indicated, Me.sup.(+) is the cation of an inorganic or organic base and R₁ " is a carboxylic amide residue or a cyano group.

III. DETAILS OF THE PROCESS OF MAKING

In order to make the compounds of the invention in which in the general formula I n=1 there may be used as oxidizing agents organic hydroperoxides such as tert.-butylhydroperoxide, or per-acids, such as m-chloroperbenzoic acid, or N-halogeno acid amides like N-bromosuccinimide. Inorganic oxidizing agents, such as hydrogen peroxide and sodium metaperiodate may also be used. Preferably two oxidation equivalents of the oxidizing agents or a small excess are employed per mol of thio compound at temperatures of about 0° to 60° C.

In order to make the compounds of the formula I in which n is 2 it is possible in addition to the just named oxidizing agents to use also agents such as chlorine, potassium permanganate, chromic acid and their salts or nitric acid and the temperature range of 0° to 120° C. Preferably, there are used four oxidation equivalents or a slight excess above it per mol of thio compound. In other words, there are used about twice the amount of oxidizing agents as employed for the above-described sulfoxidation as in the case where n is 1.

The reaction in general can be carried out at temperatures between -30° and 120° C. These temperatures should be used during the oxidation reactions.

For the synthesis of the compounds of the invention the reactants are used in about equimolar amounts. This is otherwise in case of the dehydration reaction in which a large excess of the water extracting agent is preferred.

As reaction media there may be used solvents which are inert towards the reactants. They may be used as such or in mixture with water. Their selection dependson conventional considerations having in mind the specific purpose of the reaction. As solvents or suspension agents there may be used: carboxylic acids such as acetic acid, carboxylic amides, such as dimethylformamide; carboxylic acid nitriles, such as acetonitrile; alcohols, such as methanol; ethers, such as dioxane, and many others.

If it is considered advisable there may be used as inorganic or organic bases, oxides and hydroxides of the alkali or alkali earth metals, for instance sodium or potassium hydroxide or tertiary amines, such as triethylamine or N,N-dimethylaniline.

Suitable alkylating agents are for instance alkyl halides, preferably iodides and bromides, as well as esters of sulfuric acid, such as dimethylsulfate or esters of aromatic sulfonic acids, such as methyltosylate.

Suitable dehydration agents are particularly inorganic agents, such as mineral acids, for instance concentrated sulfuric acid or polyphosphoric acid, inorganic halides, for instance, phosphorus pentachloride, phosphorus trichloride, titanium tetrachloride and many others. Also organic agents may be used such as carboxylic acid chlorides, for instance acetylchloride, carboxylic acid anhydride, such as trifluoroacetic acid anhydride, carbodiimides, such as dicyclohexylcarbodiimide and many others. The isolation of the formed compounds of the invention may be carried out by distilling off the solvent at atmospheric or reduced pressure or by precipitation with water or a slightly polar organic solvent such as diethylether or by crystallization.

PREFERRED EMBODIMENTS OF THE INVENTION Examples for compounds wherein n is 1 or 2.

The following examples will illustrate the making of compounds of the invention as shown in Formula I wherein n is 1 or 2.

EXAMPLE 1 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide

A solution of 20.0 g of 5-ethylthio-1,3,4-thiadiazole-2-carboxylic acid ethylamide in 70 ml of acetic acid is heated to 80° C. When this temperature is reached 31.3 g of a 30% concentration of aqueous hydrogen peroxide are added dropwise resulting in boiling of the solution. When no more heat development is observed the solution is subjected to another hour of reflux boiling whereupon it is cooled to room temperature, stirred in ice water and subjected to removal by suction of the precipitated compound.

Yield: 17.8 g (78% of the theoretical value); M.p.: 116° C.

EXAMPLE 2 5-ethylsulfinyl-1,3,4-thiadiazole-2-carboxamide

38 g of 5-ethylthio-1,3,4-thiadiazole-2-carboxamide are dissolved at 40° C. in 400 ml of glacial acetic acid and are then slowly reacted with 22.6 ml of a 30% hydrogen peroxide upon stirring. The solution is kept for another 3 hours at the same temperature. At the end of this period the oxidation is sufficiently complete not to require any further addition of heat. After standing overnight the reaction mixture is stirred into two liters of icewater resulting in the precipitation of a solid material which is removed by suction and recrystallized from isopropanol.

Yield: 15.2 g (37% of the theoretical value); M.p.: 103° C.

EXAMPLE 3 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxamide

9.3 g of 5-methylthio-1,3,4-thiadiazole-2-carboxamide were dissolved at 80° C. in 50 ml acetic acid and were reacted with 18 ml of 30% hydrogen peroxide upon stirring so as to permit to keep the solution during boiling under reflux. After the addition is complete the boiling was continued for 30 minutes. After cooling to room temperature the reaction product precipitated. It was removed by suction and dried.

Yield: 7.3 g (67% of the theoretical value); M.p.: 185° C.

EXAMPLE 4 5-isopropylsulfonyl-1,3,4-thiadiazole-2-carbonitrile

40 ml of 30% hydrogen peroxide were added dropwise under stirring at 70° C. to a solution of 46.0 g of 5-isopropylthio-1,3,4-thiadiazole-2-carboxamide in 250 ml of glacial acetic acid. This caused the solution to boil. Then 40 ml of perhydrol were furthermore added causing the reaction solution to remain boiling without addition of any heat. The mixture was then subjected to stirring for another 30 minutes whereupon it was cooled which caused the reaction product to crystallize out at 30° C. By adding icewater the precipitation was completed. The crystallate was removed by suction and dried in a vacuum.

Yield: 45.0 g (86% of the theoretical amount); M.p.: 162° C.

EXAMPLE 5 5-methylsulfonyl-1,3,4-thiadiazole-2-carbonitrile

A mixture of 20 ml titanium tetrachloride in 50 ml carbon tetrachloride was added dropwise at 0° to 5° C. upon stirring to 350 ml tetrahydrofuran. Subsequently, 2-methylsulfonyl-1,3,4-thiadiazole-2-carboxamide was added in batches at room temperature in an amount of 20.7 g. After continued stirring for 1 hour a solution of 50 ml triethylamine in 50 ml tetrahydrofuran was dropped into the mixture within a period of 60 minutes. The mixture was then reacted with 50 ml water, the total mixture was extracted with chloroform and the organic phase was dried over magnesium sulfate and the solvent was distilled off in a vacuum. The residue was taken up in acetic acid ethylester, subjected to boiling with activated carbon, filtered and concentrated. The residue was crystallized from chloroform/tetrahydrofuran (3:1).

Yield: 9.1 g (48% of the theoretical value); M.p.: 173°-175° C.

EXAMPLE 6 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylester

21.4 g of powdered potassium permanganate was introduced into a solution of 20.4 g of 5-methylthio-1,3,4-thiadiazole-2-caroboxylic acid ethylester in 100 ml acetic acid and 40 ml water in a manner that the temperature of the solution rose to 70° C. To complete the reaction the mixture was stirred for another 30 minutes. Thereafter, the manganese dioxide which precipitated at 10° was reduced with a solution of 19 g sodium metabisulfite in 100 ml water while cooling with ice. Upon addition of 500 ml water the desired compound precipitated. It was removed by suction, dried and recrystallized from isopropylether.

Yield: 9.4 g (40% of the theoretical value); M.p.: 48° C.

EXAMPLE 7 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid cyclohexylmethylamide

20.3 g of 5-methylthio-1,3,4-thiadiazole-2-carboxylic acid cyclohexylmethylamide were dissolved in 130 ml acetic acid and 25 ml water. 16 g pulverized potassium permanganate was then introduced upon stirring to cause the temperature to increase to 70° C. Thereafter, stirring was continued for 30 minutes. The mixture was cooled and then mixed with 300 ml ice water. The formed manganese dioxide was reduced with a solution of 14.3 g sodium metabisulfite in 100 ml water. The precipitated compound was removed by suction and recrystallized from ethanol.

Yield: 18.3 g (81% of the theoretical value); M.p.: 159° C.

In an analogous manner to the Examples 1 to 7 the following specific compounds were made:

    ______________________________________                                                                Physical                                                Compound               constants                                               ______________________________________                                         5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxamide          M.p.: 143° C.                                    5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carbonitrile         M.p.: 87° C.                                     5-isopropylsulfonyl-1,3,4-thiadiazole-                                         2-carbonitrile         M.p.: 78° C.                                     5-methylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid methylamide                                                                         M.p.: 135° C.                                    5-methylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-dimethylamide                                                                       M.p.: 91° C.                                     5-isobutylsulfonyl-1,3,4-thiadiazole-2-                                        carboxamide            M.p.: 125° C.                                    5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-methylamide                                                                         M.p.: 169° C.                                    5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-dimethylamide                                                                       M.p.: 58° C.                                     5-propylsulfonyl-1,3,4-thiadiazole-                                            2-carboxamide          M.p.: 153° C.                                    5-propylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-methylamide                                                                         M.p.: 148° C.                                    5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-butylamide                                                                          M.p.: 77° C.                                     5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-ethylester                                                                          M.p.: 55° C. -5-ethylsulfonyl-1,3,4-thiadiaz                            ole-                                                    2-carboxylic acid-cyclopropylamide                                                                    M.p.: 135° C.                                    5-methylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-methylester                                                                         M.p.: 95° C.                                     5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-propylamide                                                                         M.p.: 105° C.                                    5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-(N-butyl,N-methyl)-                                                                 n.sub.D.sup.20 : 1,5310                                 amide                                                                          5-ethylsulfonyl-1,3,4-thiadiazole-2-                                           carboxylic acid-(2-methoxyethyl)-amide                                                                M.p.: 77° C.                                     5-ethylsulfonyl-1,3,4-thiadiazole-2-                                           carboxylic acid-(3-methoxypropyl)-amide                                                               M.p.: 71° C.                                     5-ethylsulfonyl-1,3,4-thiadiazole-2-                                           carboxylic acid-isopropylamide                                                                        M.p.: 85° C.                                     5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-allylamide                                                                          M.p.: 61° C. -5-ethylsulfonyl-1,3,4-thiadiaz                            ole-                                                    2-carboxylic acid-octylamide                                                                          M.p.: 82° C.                                     5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-N,N-tetramethylene-                                          amide                  M.p.: 91° C.                                     5-ethylsulfonyl-1,3,4-thiadiazole-2-                                           carboxylic acid-(N,N-3-oxapentamethy-                                          leneamide              M.p.: 83° C.                                     5-ethylsulfonyl-1,3,4-thiadiazole-2-                                           carboxylic acid-cyclooctylamide                                                                       M.p.: 97° C.                                     5-propylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-ethylester                                                                          M.p.: 38° C.                                     5-propylsulfonyl-1,3,4-thiadiazole-                                            2-carbonitrile         M.p.: 83° C.                                     5-propylsulfinyl-1,3,4-thiadiazole-                                            2-carbonitrile         M.p.: 69° C.                                     5-ethylsulfinyl-1,3,4-thiadiazole-                                             2-carbonitrile         M.p.: 78° C.                                     5-methylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-ethylamide                                                                          M.p.: 137° C.                                    5-methylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-isopropylamide                                                                      M.p.: 108° C.                                    5-methylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-propylamide                                                                         M.p.: 115° C.                                    5-methylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-butylamide                                                                          M.p.: 95° C.                                     5-methylsulfinyl-1,3,4-thiadiazole-                                            2-carboxylic acid-propylamide                                                                         M.p.: 95° C.                                     5-methylsulfinyl-1,3,4-thiadiazole-                                            2-carboxylic acid-butylamide                                                                          M.p.: 88° C.                                     5-propylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-ethylamide                                                                          M.p.: 105° C.                                    5-propylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-propylamide                                                                         M.p.: 103° C.                                    5-propylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-allylamide                                                                          M.p.: 70° C.                                     5-sec.-butylsulfonyl-1,3,4-thiadia-                                                                   n.sub.D.sup.20 : 1,5168                                 zole-2-carboxylic acid-ethylester                                              5-sec.-butylsulfonyl-1,3,4-thiadia-                                            zole-2-carboxamide     M.p.: 127° C.                                    5-methylsulfinyl-1,3,4-thiadia-                                                zole-2-carboxylic acid-allylamide                                                                     M.p.: 68° C.                                     5-sec.-butylsulfinyl-1,3,4-thiadia-                                            zole-2-carboxamide     M.p.: 87° C.                                     5-sec.-butylsulfonyl-1,3,4-thiadia-                                            zole-2-carbonitrile    M.p.: 57° C.                                     5-propylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-isopropylamide                                                                      M.p.: 79° C.                                     5-propylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-butylamide                                                                          M.p.: 88° C.                                     5-methylsulfonyl-1,3,4-thiadiazole-                                            2-2-carboxylic acid-allylamide                                                                        M.p.: 72° C.                                     5-propylsulfinyl-1,3,4-thiadiazole-                                            2-carboxylic acid-ethylamide                                                                          M.p.: 75° C.                                     5-propylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-propylamide                                                                           M.p.: 67° C.                                     5-propylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-allylamide                                                                            M.p.: 73° C.                                     5-propylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-isopropylamide                                                                        M.p.: 76° C.                                     5-methylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-(2-methoxyethyl)-amide                                                                M.p.: 63° C.                                     5-methylsulfonyl-1,3,4-thiadiazole-2-                                          carboxylic acid-(2-methoxyethyl)-amide                                                                M.p.: 80° C.                                     5-methylsulfonyl-1,3,4-thiadiazole-2-                                          carboxylic acid-(3-methoxypropyl)-amide                                                               M.p.: 97° C.                                     5-methylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-(3-methoxypropyl)-amide                                                               M.p.: 71° C.                                     5-methylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-ethylamide                                                                            M.p.: 118° C.                                    5-methylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-isopropylamide                                                                        M.p.: 77° C.                                     5-methylsulfonyl-1,3,4-thiadiazole-2-                                          carboxylic acid-cyclopropylamide                                                                      M.p.: 171° C.                                    5-methylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-cyclopropylamide                                                                      M.p.: 149° C.                                    5-methylsulfonyl-1,3,4-thiadiazole-2-                                          carboxylic acid-N,N-trimethylenamide                                                                  M.p.: 144° C.                                    5-methylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-N,N-trimethylenamide                                                                  M.p.: 135° C.                                    5-propylsulfonyl-1,3,4-thiadiazole-2-                                          carboxylic acid-sec.-butylamide                                                                       M.p.: 45° C.                                     5-propylsulfonyl-1,3,4-thiadiazole-2-                                          carboxylic acid-dimethylamide                                                                         M.p.: 75° C.                                     5-butylsulfonyl-1,3,4-thiadiazole-2-                                           carboxamide            M.p.: 135° C.                                    5-butylsulfinyl-1,3,4-thiadiazole-2-                                           carboxamide            M.p.: 105° C.                                    5-butylsulfonyl-1,3,4-thiadiazole-2-                                           carbonitrile           M.p.: 43° C.                                     5-isobutylsulfonyl-1,3,4-thiadiazole-2-                                        carbonitrile           M.p.: 72° C.                                     5-propylsulfonyl-1,3,4-thiadiazole-2-                                          carboxylic acid-hexylamide                                                                            M.p.: 75° C.                                     5-isopropylsulfonyl-1,3,4-thiadiazole-                                         2-carboxylic acid-cyclohexylmethylamide                                                               M.p.: 134° C.                                    5-isopropylsulfinyl-1,3,4-thiadiazole-                                         2-carboxylic acid-cyclohexylmethylamide                                                               M.p.: 139° C.                                    5-propylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-butylamide                                                                            M.p.: 64° C.                                     5-propylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-sec.-butylamide                                                                       M.p.: 60° C.                                     5-propylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-hexylamide                                                                            M.p.: 68° C.                                     5-propylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-dimethylamide                                                                         M.p.: 64° C.                                     5-methylsulfinyl-1,3,4-thiadiazole-2-                                          carbonitrile           M.p.: 114° C.                                    5-methylsulfinyl-1,3,4-thiadiazole-                                            2-carboxamide          M.p.: 163° C.                                    5-isopropylsulfinyl-1,3,4-thiadiazole-                                         2-carboxamide          M.p.: 135° C.                                                           (decomposed)                                            5-isopropylsulfinyl-1,3,4-thiadiazole-                                         2-carbonitrile         n.sub.D.sup.20 : 1,5812                                 5-pentylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-ethylester                                                                          n.sub.D.sup.20 : 1,5130                                 5-pentylsulfonyl-1,3,4-thiadiazole-                                            2-carbonitrile         M.p.: 51° C.                                     5-hexylsulfonyl-1,3,4-thiadiazole-                                             2-carbonitrile         M.p.: 39° C.                                     5-pentylsulfonyl-1,3,4-thiadiazole-                                            2-carboxamide          M.p.: 151° C.                                    5-hexylsulfonyl-1,3,4-thiadiazole-                                             2-carboxamide          M.p.: 139° C.                                    5-propylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-N,N-trimethyleneamide                                                               M.p.: 127° C.                                    5-butylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-N,N-trimethylenamide                                                                M.p.: 102° C.                                    5-butylsulfinyl-1,3,4-thiadiazole-                                             2-carbonitrile         M.p.: 68° C.                                     5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-N,N-trimethyleneamide                                                               M.p.: 107° C.                                    5-isopropylsulfonyl-1,3,4-thiadiazole-                                         2-carboxylic acid-methylamide                                                                         M.p.: 207° C.                                    5-isopropylsulfonyl-1,3,4-thiadiazole-                                         2-carboxylic acid-ethylamide                                                                          M.p.: 131° C.                                    5-isopropylsulfonyl-1,3,4-thiadiazole-                                         2-carboxylic acid-isopropylamide                                                                      M.p.: 111° C.                                    5-isopropylsulfonyl-1,3,4-thiadiazole-                                         2-carboxylic acid-propylamide                                                                         M.p.: 94° C.                                     5-isopropylsulfonyl-1,3,4-thiadiazole-                                         2-carboxylic acid-butylamide                                                                          M.p.: 72° C.                                     5-isopropylsulfonyl-1,3,4-thiadiazole-                                         2-carboxylic acid-isobutylamide                                                                       M.p.: 92° C.                                     5-isopropylsulfonyl-1,3,4-thiadiazole-                                         2-carboxylic acid-sec.-butylamide                                                                     M.p.: 92° C.                                     5-isopropylsulfinyl-1,3,4-thiadiazole-                                         2-carboxylic acid-methylamide                                                                         M.p.: 184                                                                      (decomposed)                                            5-isopropylsulfinyl-1,3,4-thiadiazole-                                         2-carboxylic acid-ethylamide                                                                          M.p.: 118° C.                                    5-(2-propenylsulfinyl)-1,3,4-thiadia-                                          zole-2-carboxylic acid-methylamide                                                                    M.p.: 125° C.                                    5-methylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-N-ethyl-N-butylamide                                                                n.sub.D.sup.20 : 1,5312                                 5-isopropylsulfinyl-1,3,4-thiadiazole-                                         2-carboxylic acid-propylamide                                                                         M.p.: 84° C.                                     5-isopropylsulfonyl-1,3,4-thiadiazole-                                         2-carboxylic acid-isopropylamide                                                                      M.p.: 84° C.                                     5-isopropylsulfonyl-1,3,4-thiadiazole-                                         2-carboxylic acid-dimethylamide                                                                       M.p.: 82° C.                                     5-butylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-methylamide                                                                         M.p.: 146° C.                                    5-butylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-ethylamide                                                                          M.p.: 87° C.                                     5-butylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-propylamide                                                                         M.p.: 101° C.                                    5-butylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-(2-methoxyethyl)amide                                                               M.p.: 63° C.                                     5-butylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-isopropylamide                                                                      M.p.: 99° C.                                     5-butylsulfinyl-1,3,4-thiadiazole-                                             2-carboxylic acid-methylamide                                                                         M.p.: 112° C.                                    5-butylsulfinyl-1,3,4-thiadiazole-                                             2-carboxylic acid-ethylamide                                                                          M.p.: 72° C.                                     5-butylsulfinyl-1,3,4-thiadiazole-                                             2-carboxylic acid-propylamide                                                                         M.p.: 84° C.                                     5-butylsulfinyl-1,3,4-thiadiazole-                                             2-carboxylic acid-(2-methoxyethyl)-amide                                                              M.p.: 54° C.                                     5-butylsulfinyl-1,3,4-thiadiazole-                                             2-carboxylic acid-isopropylamide                                                                      M.p.: 57° C.                                     5-methylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-N-butyl-N-methylamide                                                               n.sub.D.sup.20 : 1,5330                                 5-methylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-N-isobutyl-N-methyl-                                                                n.sub.D.sup.20 : 1,5291                                 5-methylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-N,N-diethylamide                                                                    M.p.: 98° C.                                     5-sec.-butylsulfonyl-1,3,4-thiadiazole-                                        2-carboxylic acid-methylamide                                                                         M.p.: 150° C.                                    5-sec.-butylsulfonyl-1,3,4-thiadiazole-                                        2-carboxylic acid-ethylamide                                                                          M.p.: 79° C.                                     5-cyclohexylsulfonyl-1,3,4-thiadiazole-                                        2-carboxamide          M.p.: 176° C.                                    5-cyclohexylsulfonyl-1,3,4-thiadiazole-                                        2-carbonitrile         M.p.: 140° C.                                    5-methylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-N,N-dipropylamide                                                                   M.p.: 55° C.                                     5-sec.-butylsulfonyl-1,3,4-thiadiazole-                                        2-carboxylic acid-cyclopropylamide                                                                    M.p.: 95° C.                                     5-pentylsulfinyl-1,3,4-thiadiazole-                                            2-carbonitrile         M.p.: 65° C.                                     5-hexylsulfinyl-1,3,4-thiadiazole-                                             2-carbonitrile         M.p.: 57° C.                                     5-pentylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-methylamide                                                                         M.p.: 126° C.                                    5-hexylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-methylamide                                                                         M.p.: 108° C.                                    5-cyclohexylsulfinyl-1,3,4-thiadiazole-                                        2-carbonitrile         M.p.: 87° C.                                     5-sec.-butylsulfonyl-1,3,4-thiadiazole-                                        2-carboxylic acid-(2-methoxyethyl)amide                                                               n.sub.D.sup.20 : 1,5357                                 5-sec.-butylsulfinyl-1,3,4-thiadiazole-                                        2-carboxylic acid-methylamide                                                                         M.p.: 115° C.                                    5-sec.-butylsulfinyl-1,3,4-thiadiazole-                                        2-carboxylic acid-ethylamide                                                                          n.sub.D.sup.20 : 1,5580                                 5-pentylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-ethylamide                                                                          M.p.: 90° C.                                     5-hexylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-ethylamide                                                                          M.p.: 67° C.                                     5-pentylsulfinyl-1,3,4-thiadiazole-                                            2-carboxylic acid-ethylamide                                                                          M.p.: 75° C.                                     5-hexylsulfinyl-1,3,4-thiadiazole-                                             2-carboxylic acid-ethylamide                                                                          M.p.: 75° C.                                     5-methylsulfinyl-1,3,4-thiadiazole-                                            2-carboxylic acid-N,N-diethylamide                                                                    n.sub.D.sup.20 : 1,5650                                 5-sec.-butylsulfonyl-1,3,4-thiadiazole-                                        2-carboxylic acid-isopropylamide                                                                      M.p.: 77° C.                                     5-sec.-butylsulfinyl-1,3,4-thiadiazole-                                        2-carboxylic acid-cyclopropylamide                                                                    n.sub.D.sup.20 : 1,5671                                 5-pentylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-propylamide                                                                         M.p.: 86° C.                                     5-pentylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-isopropylamide                                                                      M.p.: 95° C.                                     5-pentylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-cyclopropylamide                                                                    M.p.: 106° C.                                    5-pentylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-butylamide                                                                          M.p.: 92° C.                                     5-pentylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-sec.-butylamide                                                                     M.p.: 89° C.                                     5-pentylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-isobutylamide                                                                       M.p.: 106° C.                                    5-pentylsulfinyl-1,3,4-thiadiazole-                                            2-carboxylic acid-propylamide                                                                         M.p.: 79° C.                                     5-pentylsulfinyl-1,3,4-thiadiazole-                                            2-carboxylic acid-isopropylamide                                                                      M.p.: 61° C.                                     5-pentylsulfinyl-1,3,4-thiadiazole-                                            2-carboxylic acid-allylamide                                                                          M.p.: 74° C.                                     5-pentylsulfinyl-1,3,4-thiadiazole-                                            2-carboxylic acid-cyclopropylamide                                                                    M.p.: 90° C.                                     5-pentylsulfinyl-1,3,4-thiadiazole-                                            2-carboxylic acid-butylamide                                                                          M.p.: 85° C.                                     5-pentylsulfinyl-1,3,4-thiadiazole-                                            2-carboxylic acid-sec.-butylamide                                                                     M.p.: 59° C.                                     5-pentylsulfinyl-1,3,4-thiadiazole-                                            2-carboxylic acid-isobutylamide                                                                       M.p.: 80° C.                                     5-cyclopentylsulfonyl-1,3,4-thiadiazole-                                       2-carboxylic acid-methylamide                                                                         M.p.: 203° C.                                    5-cyclopentylsulfonyl-1,3,4-thiadiazole-                                       2-carboxylic acid-ethylamide                                                                          M.p.: 115° C.                                    5-sec.-butylsulfinyl-1,3,4-thiadiazole-                                        2-carboxylic acid-(2-methoxyethyl)-amide                                                              n.sub.D.sup.20 : 1,5519                                 5-sec.-butylsulfonyl-1,3,4-thiadiazole-                                        2-carboxylic acid-(3-methoxypropyl)-amide                                                             n.sub.D.sup.20 : 1,5324                                 5-cyclopentylsulfonyl-1,3,4-thiadiazole-                                       2-carboxylic acid-propylamide                                                                         M.p.: 95° C.                                     5-cyclopentylsulfonyl-1,3,4-thiadiazole-                                       2-carboxylic acid-isopropylamide                                                                      M.p.: 77° C.                                     5-cyclopentylsulfonyl-1,3,4-thiadiazole-                                       2-carboxylic acid-cyclopropylamide                                                                    M.p.: 90° C.                                     5-cyclopentylsulfonyl-1,3,4-thiadiazole-                                       2-carboxylic acid-butylamide                                                                          M.p.: 76° C.                                     5-cyclopentylsulfonyl-1,3,4-thiadiazole-                                       2-carboxylic acid-dimethylamide                                                                       M.p.: 56° C.                                     5-pentylsulfonyl-1,3,4-thiadiazole-2-                                          carboxylic acid-dimethylamide                                                                         M.p.: 61° C.                                     5-pentylsulfonyl-1,3,4-thiadiazole-2-                                          carboxylic acid-(3-methoxypropyl)-amide                                                               M.p.: 56° C.                                     5-hexylsulfonyl-1,3,4-thiadiazole-2-                                           carboxylic acid-propylamide                                                                           M.p.: 80° C.                                     5-hexylsulfonyl-1,3,4-thiadiazole-2-                                           carboxylic acid-isopropylamide                                                                        M.p.: 91° C.                                     5-hexylsulfonyl-1,3,4-thiadiazole-2-                                           carboxylic acid-(2-methoxyethyl)-amide                                                                M.p.: 46° C.                                     5-hexylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-(3-methoxypropyl)-                                           amide                  M.p.: 57° C.                                     5-cyclopentylsulfinyl-1,3,4-thiadiazole-                                       2-carboxylic acid-methylamide                                                                         M.p.: 168° C.                                                           (decomposed)                                            5-cyclopentylsulfinyl-1,3,4-thiadiazole-                                       2-carboxylic acid-ethylamide                                                                          M.p.: 93° C.                                     5-methylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-N,N-diisopropyl-                                             amide                  n.sub.D.sup.20 : 1,5240                                 5-sec.-butylsulfinyl-1,3,4-thiadiazole-                                        2-carboxylic acid-(3-methoxypropyl)-                                           amide                  n.sub.D.sup.20 : 1,5489                                 5-hexylsulfinyl-1,3,4-thiadiazole-                                             2-carboxylic acid-propylamide                                                                         M.p.: 71° C.                                     5-hexylsulfinyl-1,3,4-thiadiazole-                                             2-carboxylic acid-isopropylamide                                                                      M.p.: 61° C.                                     5-hexylsulfinyl-1,3,4-thiadiazole-                                             2-carboxylic acid-(2-propenyl)-amide                                                                  M.p.: 69° C.                                     5-hexylsulfinyl-1,3,4-thiadiazole-                                             2-carboxylic acid-cyclopropylamide                                                                    M.p.: 90° C.                                     5-hexylsulfinyl-1,3,4-thiadiazole-                                             2-carboxylic acid-(2-methoxyethyl)-                                            amide                  M.p.: 57° C.                                     5-hexylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-cyclopropylamide                                                                    M.p.: 83° C.                                     5-hexylsulfinyl-1,3,4-thiadiazole-                                             2-carboxylic acid-(3-methoxypropyl)-                                           amide                  M.p.: 53° C.                                     ______________________________________                                    

The compounds of the invention are colorless and non-smelling oils or crystalline bodies which have a good solubility in polar organic solvents such as carboxylic acid amides, for instance dimethylformamide; carboxylic acid nitriles, for instance acetonitrile, and alcohols such as methanol. They are less soluble in hydrocarbons, for instance hexane, and halogenated hydrocarbons, for instance dichloromethane. They are insoluble in water.

EXAMPLES ILLUSTRATING THE STARTING PRODUCTS AND COMPOUNDS OF THE INVENTION WHEREIN N=0.

The following examples illustrate the making of the compounds of the invention coming under formula I wherein n=0. These compounds are starting products or intermediate products for making the compounds of the invention in which n is 1 or 2. However, in view of their partial nematocidal properties they may also be used directly as nematocides in agriculture and horticulture.

EXAMPLE 8 (a) 3-(ethoxyoxalyl)-dithiocarbazinic acid, potassium salt

91.5 g of carbon disulfide were added upon stirring to a suspension of 198 g of oxalic acid ethylesterhydrazide in 1 l ethanol while stirring. At a temperature between 10° and 15° C. there was then added dropwise a solution of 98.7 g of 85% concentration potassium hydroxide in 900 ml ethanol. Stirring was continued for 1 hour and the formed salt was extracted with 3 l diethylether. The potassium salt was removed by suction, washed with ether and dried in a vacuum.

Yield: 357 g (97% of the theoretical amount);

M.p. : 160° C.

(b) 5-thioxo-1,3,4-thiadiazoline-2-carboxylic acid ethylester

440 g of the product obtained in (a), that is 3-(ethoxyoxalyl)-dithiocarbazinic acid, potassium salt were introduced into 1.2 l concentrated sulfuric acid at a temperature of 20°-30° C. The mixture was stirred until the compounds was completely dissolved. After standing overnight the solution was stirred in 5 l icewater. The percipitated compound was removed by suction, washed with water, and dried in a vacuum at 40° C.

Yield: 163.5 g (48% of the theoretical value);

M.p. : 91° C.

(c) 5-ethylthio-1,3,4-thiadiazole-2-carboxylic acid ethylester

99.9 g of ethyliodide were added to a suspension of 121.3 g of the compound obtained in (b), i.e. 5-thioxo-1,3,4-thiadiazoline-2-carboxylic acid ethylester in 350 ml ethanol. Thereafter, 64.7 g of triethylamine were added dropwise at a temperature between 20° and 25° C. while cooling and stirring the mixture. Stirring was then continued for another 2 hours. The mixture was thereafter poured into 1.5 l icewater. The precipitating oil was extracted with 300 ml chloroform. The chloroform phase was separated, twice washed with water and dried on magnesium sulfate. The solvent was distilled off at a reduced pressure.

Yield: 99.3 g (71% of the theoretical value);

n_(D) ²⁰ : 1,5782.

EXAMPLE 9 5-ethylthio-1,3,4-thiadiazole-2-carboxylic acid ethylamide

54 g of an aqueous 50% ethylamine solution were added to 43.7 g of the compound obtained in Example 8(c), that is ethylthio-1,3,4-thiadiazole-2-carboxylic acid ethyester. This caused the temperature to rise to 46° C. The solution was subsequently heated to boiling point for another 15 minutes. It was then cooled to 4° C. and reacted with 50 ml icewater. The precipitated compound was removed by suction.

Yield: 30.0 g (69% of the theoretical value);

M.p. : 85° C.

EXAMPLE 10 5-methylthio-1,3,4-thiadiazole-2-carboxylic acid ethylester

61 g of dithiocarbazinic acid methylester were dissolved in 400 ml dioxane. By adding dropwise upon stirring 75 g of oxalic acid ethylesterchloride, the temperature was caused to rise to 75° C. At this temperature the solution was subjected to further stirring for 30 minutes. The dioxane was distilled off in a vacuum and the oily residue was introduced in 350 ml of concentrated sulfuric acid. To complete the cyclization the reaction solution was kept for another hour at 40° C. and after cooling to room temperature was stirred into 2 l icewater. The precipitated crystals were removed by suction and recrystallized from cyclohexane.

Yield: 68.5 g (67% of the theoretical value);

M.p. : 46° C.

EXAMPLE 11 5-methylthio-1,3,4-thiadiazole-2-carboxamide

11.8 g of 5-methylthio-1,3,4-thiadiazole-2-carboxylic acid ethylester which is the compound obtained in Example 10, were mixed with 50 ml ethanol and 50 ml of a 25% aqueous ammonia solution whereupon the mixture was heated for 15 minutes on a steam bath. After cooling part of the reaction product precipitated. The precipitation was completed by adding ice water. The precipitate was then removed by suction and dried in a vacuum.

Yield: 8.9 g (88% of the theoretical amount);

M.p. : 185° C.

EXAMPLE 12 5-methylthio-1,3,4-thiadiazole-2-carbonitrile

350 ml tetrahydrofuran were added dropwise upon stirring and cooling at a temperature between 0° and 5° C. to a solution of 20 ml titanium tetrachloride in 50 ml carbon tetrachloride. There were then added at first in batches 15.3 g of 5-methylthio-1,3,4-thiadiazole-2-carboxamide as obtained in Example 11, and thereafter within a period of 1 hour 50 ml triethylamine which had been taken up in 50 ml tetrahydrofuran. After addition of 50 ml water the reaction mixture was extracted with chloroform. The extract was dried on magnesium sulfate and the solvent was removed in a vacuum. The residue was taken up in acetic acid ethylester and filtrated off from the insoluble residue. The ester phase was then treated with activated carbon and finally concentrated to dryness in a vacuum.

Yield: 11.1 g (81% of the theoretical amount);

M.p. : 118°-120° C.

EXAMPLE 13 5-methylthio-1,3,4-thiadiazole-2-carboxylic acid cyclohexyl methylamide

30.6 g of 5-methylthio-1,3,4-thiadiazole-2-carboxylic acid ethylester as obtained in Example 10, were heated to boiling point for 2 hours with 16.95 g of cyclohexylmethylamine in 150 ml ethanol. The solution was concentrated to 50 ml and the reaction product was precipitated by stirring in ice water.

Yield: 35.3 g (87% of the theoretical value);

M.P. : 103° C.

In a manner analogous to the processes of Examples 8 to 13 the following further starting products or intermediate products were obtained.

    ______________________________________                                                                Physical                                                Compound               Constants                                               ______________________________________                                         5-methylthio-1,3,4-thiadiazole-                                                2-carboxylic acid methylester                                                                         M.p.: 80° C.                                     5-methylthio-1,3,4-thiadiazole-                                                2-carboxylic acid methylamide                                                                         M.p.: 128° C.                                    5-methylthio-1,3,4-thiadiazole-                                                2-carboxylic acid dimethylamide                                                                       M.p.: 128° C.                                    5-ethylthio-1,3,4-thiadiazole-                                                 2-carboxamide          M.p.: 162° C.                                    5-ethylthio-1,3,4-thiadiazole-                                                 2-carboxylic acid methylamide                                                                         M.p.: 116° C.                                    5-ethylthio-1,3,4-thiadiazole-                                                 2-carboxylic acid dimethylamide                                                                       M.p: 53° C.                                      5-ethylthio-1,3,4-thiadiazole-                                                 2-carboxylic acid cyclopropylamide                                                                    M.p.: 91° C.                                     5-ethylthio-1,3,4thiadiazole-                                                  2-carboxylic acid butylamide                                                                          M.p.: 54° C.                                     5-propylthio-1,3,4-thiadiazole-                                                2-carboxamide          M.p.: 137° C.                                    5-propylthio-1,3,4-thiadiazle-                                                 2-carboxylic acid methylamide                                                                         M.p.: 72° C.                                     5-isopropylthio-1,3,4-thiadiazole-                                             2-carboxamide          M.p.: 154° C.                                    5-isobutylthio-1,3,4-thiadiazole-                                              2-carboxamide          M.p.: 162° C.                                    5-ethylthio-1,3,4-thiadiazole-2-                                               carbonitrile           M.p.: 40° C.                                     5-propylthio-1,3,4-thiadiazole-2-                                              carboxamide            M.p.: 142° C.                                    5-sec.-butylthio-1,3,4-thiadiazole-2-                                          carboxamide            M.p.: 119° C.                                    5-methylthio-1,3,4-thiadiazole-2-                                              carboxylic acid-propylamide                                                                           M.p.: 83° C.                                     5-methylthio-1,3,4-thiadiazole-2-                                              carboxylic acid-butylamide                                                                            M.p.: 90° C.                                     5-methylthio-1,3,4-thiadiazole-2-                                              carboxylic acid-allylamide                                                                            M.p.: 88° C.                                     5-methylthio-1,3,4-thiadiazole-2-                                              carboxylic acid-ethylamide                                                                            M.p.: 83° C.                                     5-methylthio-1,3,4-thiadiazole-2-                                              carboxylic acid-isopropylamide                                                                        M.p.: 101° C.                                    5-methylthio-1,3,4-thiadiazole-2-                                              carboxylic acid-(2-methoxyethyl)-amide                                                                M.p.: 83° C.                                     5-methylthio-1,3,4-thiadiazole-2-                                              carboxylic acid-(3-methoxypropyl)-amide                                                               M.p.: 57° C.                                     5-methylthio-1,3,4thiadiazole-2-                                               carboxylic acid-cyclopropylamide                                                                      M.p.: 130° C.                                    5-methylthio-1,3,4-thiadiazole-2-                                              carboxylic acid-N,N-trimethyleneamide                                                                 M.p.: 106° C.                                    5-butylthio-1,3,4-thiadiazole-2-                                               carboxamide            M.p.: 165° C.                                    5-hexylthio-1,3,4-thiadiazole-2-                                               carboxamide            M.p.: 150° C.                                    5-(2-methyl-2-propenylthio)-1,3,4-                                             thiadiazole-2-carboxylic acid-2-                                               propenylamide          n.sub.D.sup.20 : 1,5793                                 5-(2-methyl-2-propenylthio)-1,3,4-                                             thiadiazole-2-carboxylic acid-iso-                                             propylamide            M.p.: 69° C.                                     5-(propenylthio)1,3,4-thiadiazole                                              2-(carboxylic acid amide                                                                              M.p.: 144° C.                                    5-(2-propenylthio)-1,3,4-thiadiazole-                                          carboxylic acid-methylamide                                                                           M.p.: 87° C.                                     5-(2-propenylthio)-1,3,4-thiadiazole-                                          2-carboxylic acid-ethylamide                                                                          M.p.: 70° C.                                     5-(2-propenylthio)-1,3,4-thiadiazole-                                          2-carboxylic acid-propylamide                                                                         M.p.: 65° C.                                     5-(2-propenylthio)-1,3,4-thiadiazole-                                          2-carboxylic acid-isopropylamide                                                                      M.p: 95° C.                                      5-(2-propenylthio)-1,3,4-thiadiazole-                                          2-carboxylic acid (2-propenylamide)                                                                   M.p.: 54° C.                                     5-(2-propenylthio)-1,3,4-thiadiazole-                                          2-carboxylic acid-ethylester                                                                          n.sub.D.sup.20 : 1,5825                                 5-butylthio-1,3,4-thiadiazole-2-                                               carboxylic acid-ethylester                                                                            n.sub.D.sup.20 : 1,5540                                 5-butylthio-1,3,4-thiadiazole-2-                                               carboxylic acid-methylamide                                                                           M.p.: 83° C.                                     5-butylthio-1,3,4-thiadiazole-2-                                               carboxylic acid-propylamide                                                                           M.p.: 52° C.                                     5-butylthio-1,3,4-thiadiazole-2-                                               carboxylic acid ethylamide                                                                            M.p.: 67° C.                                     5-butylthio-1,3,4-thiadiazole-2-                                               carboxylic acid-isopropylamide                                                                        M.p.: 79° C.                                     5-isopropylthio-1,3,4-thiadiazole-2-                                           carboxylic acid-butylamide                                                                            M.p.: 53° C.                                     5-sec.-butylthio-1,3,4-thiadiazole-                                            2-carboxylic acid-ethylester                                                                          n.sub.D.sup.20 : 1,5527                                 5-sec.-butylthio-1,3,4-thiadiazole-                                            2-carboxylic acid-methylamide                                                                         n.sub.D.sup.20 : 1,5762                                 5-sec.-butylthio-1,3,4-thiadiazole-                                            2-carboxylic acid-ethylamide                                                                          n.sub.D.sup.20 : 1,5651                                 5-cyclohexylthio-1,3,4-thiadiazole-                                            2-carboxamide          M.p.: 158° C.                                    5-(2-propinylthio)-1,3,4-thiadiazole-                                          2-carboxylic acid-amide                                                                               M.p.: 180° C.                                    5-pentylthio-1,3,4-thiadiazole-                                                2-carboxylic acid-methylamide                                                                         M.p.: 82° C.                                     5-hexylthio-1,3,4-thiadiazole-                                                 2-carboxylic acid-methylamide                                                                         M.p.: 80° C.                                     5-sec.-butylthio-1,3,4-thiadiazole-                                            2-carboxylic acid-(2-methoxyethyl)-                                            amide                  n.sub.D.sup.20 : 1,5585 -5-sec.-butylthio-1,3,4-thi                            adiazole-                                               2-carboxylic acid-cyclopropylamide                                                                    M.p.: 50° C.                                     5-pentylthio-1,3,4-thiadiazole-                                                2-carboxylic acid-isobutylamide                                                                       M.p.: 80° C.                                     5-hexylthio-1,3,4-thiadiazole-                                                 2-carboxylic acid-propylamide                                                                         M.p.: 61° C.                                     5-sec.-butylthio-1,3,4-thiadiazole-                                            2-carboxylic acid-(3-methoxypropyl)-                                           amide                  n.sub.D.sup.20 : 1,5566                                 5-pentylthio-1,3,4-thiadiazole-                                                2-carboxylic acid-cyclopropylamide                                                                    M.p.: 87° C.                                     5-(2-propinylthio)-1,3,4-thiadiazole-                                          2-carboxylic acid-ethylester                                                                          M.p.: 57° C.                                     5-pentylthio-1,3,4-thiadiazole-                                                2-carboxylic acid-(2-propenyl)-amide                                                                  M.p.: 60° C.                                     5-hexylthio-1,3,4-thiadiazole-                                                 2-carboxylic acid-(2-propenyl)-amide                                                                  M.p.: 90° C.                                     5-hexylthio-1,3,4-thiadiazole-                                                 2-carboxylic acid-cyclopropylamide                                                                    M.p.: 54° C.                                     5-hexylthio-1,3,4-thiadiazole-2-                                               carboxylic acid-(2-methoxyethyl)-amide                                                                M.p.: 52° C.                                     ______________________________________                                    

These compounds are soluble in carboxylic acids, carboxylic amides, carboxylic acid esters and halogenated hydrocarbons. They are less soluble in hydrocarbons and insoluble in water.

EXAMPLES ILLUSTRATING USES AND ACTIVITIES

The following examples are furnished to illustrate the various uses and the superior fungicidal activity of the compounds of the invention.

EXAMPLE 14 Threshold concentration test for use of the compounds against Pythium ultimum

A 20% concentration of certain pulverulent active agents as listed below were mixed in uniform manner into a soil which had been heavily infested by Pythium ultimum. The thus treated soil was then placed into clay dishes of a capacity of 0.5 l earth. Without any intermediate time lapse 20 grain of garden peas (Pisum sativum L. convar. medullare Alef.) of the type "Wunder von Kelvedon" were then seeded into each of the clay dishes. After a cultivation period of three weeks at 20° to 24° C. in a hothouse the number of sound peas was determined and a root evaluation was carried out. The active agents amounts and results appear from the following table.

The root evaluation was carried out on a scale from 1 to 4 as follows:

4=white roots without fungous necrosis;

3=white roots, minor fungous necrosis;

2=brown roots, already more pronounced fungous necrosis;

1=heavy fungous necrosis, roots rotted.

    ______________________________________                                                        Concentra-       root                                                          tion of number   evalua-                                                       agent in                                                                               of sound tion                                                          mg/l soil                                                                              peas     (1-4)                                          ______________________________________                                         Active agent                                                                   5-methylsulfonyl-1,3,4-                                                                         20 mg     16       4                                          thiadiazole-2-carboxamide                                                                       40 mg     18       4                                                           80 mg     20       4                                          5-methylsulfonyl-1,3,4-                                                                         20 mg     17       3                                          thiadiazole-2-carbonitrile                                                                      40 mg     16       4                                                           80 mg     20       4                                          5-ethylsulfonyl-1,3,4-                                                                          20 mg     18       2                                          thiadiazole-2-carboxamide                                                                       40 mg     18       4                                                           80 mg     20       4                                          5-ethylsulfonyl-1,3,4-                                                                          20 mg     19       2                                          thiadiazole-2-carbonitrile                                                                      40 mg     20       4                                                           80 mg     20       4                                          5-ethylsulfinyl-1,3,4-                                                                          20 mg     15       2                                          thiadiazole-2-carboxamide                                                                       40 mg     20       4                                                           80 mg     20       4                                          5-isopropylsulfonyl-1,3,4-                                                                      20 mg     17       4                                          thiadiazole-2-carboxamide                                                                       40 mg     18       4                                                           80 mg     19       4                                          5-isopropylsulfonyl-1,3,4-                                                                      20 mg     18       2                                          thiadiazole-2-carbonitrile                                                                      40 mg     20       4                                                           80 mg     19       4                                          5-methylsulfonyl-1,3,4-                                                                         20 mg     20       4                                          thiadiazole-2-carboxylic                                                                        40 mg     18       4                                          acid-methylamide 80 mg     18       4                                          5-methylsulfonyl-1,3,4-                                                                         20 mg     18       4                                          thiadiazole-2-carboxylic                                                                        40 mg     20       4                                          acid-dimethylamide                                                                              80 mg     18       4                                          5-isobutylsulfonyl-1,3,4-                                                                       20 mg     15       1                                          thiadiazole-2-carboxamide                                                                       40 mg     18       4                                                           80 mg     18       4                                          5-ethylsulfonyl-1,3,4-                                                                          20 mg     17       4                                          thiadiazole-2-carboxylic                                                                        40 mg     15       4                                          acid-methylamide 80 mg     19       4                                          5-ethylsulfonyl-1,3,4-                                                                          20 mg     13       4                                          thiadiazole-2-carboxylic                                                                        40 mg     13       4                                          acid-dimethylamide                                                                              80 mg     15       4                                          5-propylsulfonyl-1,3,4-                                                                         20 mg     12       1                                          thiadiazole-2-carboxamide                                                                       40 mg     19       4                                                           80 mg     17       4                                          5-propylsulfonyl-1,3,4-                                                                         20 mg     19       4                                          thiadiazole-2-carboxylic                                                                        40 mg     16       4                                          acid-methylamide 80 mg     15       4                                          5-ethylsulfonyl-1,3,4-                                                                          20 mg     8        1                                          thiadiazole-2-carboxylic                                                                        40 mg     16       4                                          acid-butylamide  80 mg     20       4                                          5-ethylsulfonyl-1,3,4-                                                                          20 mg     15       4                                          thiadiazole-2-carboxylic                                                                        40 mg     16       4                                          acid-ethylamide  80 mg     16       4                                          5-methylsulfinyl-1,3,4-thia-                                                                    20 mg     19       4                                          diazole-2-carbonitrile                                                                          40 mg     20       4                                                           80 mg     20       4                                          5-ethylsulfinyl-1,3,4-thia-                                                                     20 mg     20       4                                          diazole-2-carbonitrile                                                                          40 mg     19       4                                                           80 mg     19       4                                          5-propylsulfinyl-1,3,4-thia-                                                                    20 mg     9        1                                          diazole-2-carbonitrile                                                                          40 mg     16       4                                                           80 mg     18       4                                          5-isopropylsulfinyl-1,3,4-                                                                      20 mg     17       3                                          thiadiazole-2-carbonitrile                                                                      40 mg     17       4                                                           80 mg     19       4                                          5-butylsulfinyl-1,3,4-thia-                                                                     20 mg     18       4                                          diazole-2-carbontrile                                                                           40 mg     18       4                                                           80 mg     20       4                                          5-ethylsulfonyl-1,3,4-thia-                                                                     20 mg     20       4                                          diazole-2-carboxylic acid-                                                                      40 mg     19       4                                          N,N-trimethylenamide                                                                            80 mg     20       4                                          5-propylsulfonyl-1,3,4-thia-                                                                    20 mg     6        1                                          diazole-2-carboxylic acid-                                                                      40 mg     19       4                                          N,N-trimethyleneamide                                                                           80 mg     18       4                                          5-propylsulfonyl-1,3,4-thia-                                                                    20 mg     10       1                                          diazole-2-carboxylic acid-                                                                      40 mg     19       3                                          (3-chloropropyl)-amide                                                                          80 mg     19       4                                          5-propylsulfinyl-1,3,4-thia-                                                                    20 mg     12       1                                          diazole-2-carboxylic acid-                                                                      40 mg     18       4                                          dimethylamide    80 mg     19       4                                          5-propylsulfonyl-1,3,4-thiadia-                                                                 20 mg     17       2                                          zole-2-carboxylic acid-                                                                         40 mg     20       4                                          dimethylamide    80 mg     19       4                                          5-methylsulfonyl-1,3,4-thia-                                                                    20 mg     19       4                                          diazole-2-carboxylic acid-                                                                      40 mg     18       4                                          allylamide       80 mg     18       4                                          5-methylsulfinyl-1,3,4-thia-                                                                    20 mg     20       4                                          diazole-2-carboxylic acid-                                                                      40 mg     19       4                                          allylamide       80 mg     18       4                                          5-ethylsulfonyl-1,3,4-thiadia-                                                                  20 mg     14       2                                          zole-2-carboxylic acid-tetra-                                                                   40 mg     20       4                                          methyleneamide   80 mg     20       4                                          5-propylsulfonyl-1,3,4-thia-                                                                    20 mg     9        1                                          diazole-2-carboxylic acid-                                                                      40 mg     20       4                                          isopropylamide   80 mg     18       4                                          5-propylsulfinyl-1,3,4-thia-                                                                    20 mg     15       2                                          diazole-2-carboxylic acid-                                                                      40 mg     19       4                                          allylamide       80 mg     19       4                                          5-methylsulfonyl-1,3,4-thia-                                                                    20 mg     9        1                                          diazole-2-carboxylic acid-                                                                      40 mg     20       4                                          (3-methoxypropyl)-amide                                                                         80 mg     19       4                                          5-methylsulfinyl-1,3,4-thia-                                                                    20 mg     18       2                                          diazole-2-carboxylic acid-                                                                      40 mg     18       4                                          ethylamide       80 mg     19       4                                          5-methylsulfinyl-1,3,4-thia-                                                                    20 mg     19       4                                          diazole-2-carboxylic acid-                                                                      40 mg     19       4                                          isopropylamide   80 mg     20       4                                          5-methylsulfonyl-1,3,4-thiadia-                                                                 20 mg     13       1                                          zole-2-carboxylic acid-                                                                         40 mg     20       4                                          cyclopropylamide 80 mg     20       4                                          5-methylsulfinyl-1,3,4-thia-                                                                    20 mg     15       1                                          diazole-2-carboxylic acid-                                                                      40 mg     20       4                                          cyclopropylamide 80 mg     20       4                                          5-methylsulfonyl-1,3,4-thia-                                                                    20 mg     19       4                                          diaxole-2-carboxylic acid-                                                                      40 mg     20       4                                          N,N-trimethyleneamide                                                                           80 mg     20       4                                          5-methylsulfinyl-1,3,4-thia-                                                                    20 mg     12       2                                          diazole-2-carboxylic acid-                                                                      40 mg     16       4                                          N,N-trimethyleneamide                                                                           80 mg     19       4                                          5-butylsulfonyl-1,3,4-thia-                                                                     20 mg     11       1                                          diazole-2-carboxamide                                                                           40 mg     20       4                                                           80 mg     18       4                                          5-butylsulfinyl-1,3,4-thia-                                                                     20 mg     10       1                                          diazole-2-carboxamide                                                                           40 mg     15       4                                                           80 mg     19       4                                          5-methylsulfonyl-1,3,4-thia-                                                                    20 mg     15       4                                          diazole-2-carboxylic acid-                                                                      40 mg     15       4                                          ethylamide       80 mg     15       4                                          5-methylsulfonyl-1,3,4-thia-                                                                    20 mg     15       4                                          diazole-2-carboxylic acid-                                                                      40 mg     18       4                                          isopropylamide   80 mg     15       4                                          5-methylsulfonyl-1,3,4-thia-                                                                    20 mg     15       4                                          diazole-2-carboxylic acid-                                                                      40 mg     15       4                                          propylamide      80 mg     15       4                                          5-methylsulfonyl-1,3,4-thia-                                                                    20 mg     14       2                                          diazole-2-carboxylic acid-                                                                      40 mg     15       4                                          butylamide       80 mg     16       4                                          5-methylsulfinyl-1,3,4-thia-                                                                    20 mg     14       4                                          diazole-2-carboxylic acid-                                                                      40 mg     15       4                                          propylamide      80 mg     15       4                                          5-methylsulfinyl-1,3,4-thia-                                                                    20 mg     12       2                                          diazole-2-carboxylic acid-                                                                      40 mg     15       4                                          butylamide       80 mg     17       4                                          5-propylsulfonyl-1,3,4-thia-                                                                    20 mg     14       3                                          diazole-2-carboxylic acid-                                                                      40 mg     14       4                                          ethylamide       80 mg     14       4                                          5-propylsulfonyl-1,3,4-thia-                                                                    20 mg     10       1                                          diazole-2-carboxylic acid-                                                                      40 mg     16       4                                          propylamide      80 mg     16       4                                          5-propylsulfonyl-1,3,4-thia-                                                                    20 mg     13       3                                          diazole-2-carboxylic acid-                                                                      40 mg     15       4                                          allylamide       80 mg     15       4                                          5-ethylsulfonyl-1,3,4-thia-                                                                     20 mg     16       3                                          diazole-2-carboxylic acid-                                                                      40 mg     15       3                                          isopropylamide   80 mg     16       4                                          5-ethylsulfonyl-1,3,4-thia-                                                                     20 mg     11       1                                          diazole-2-carboxylic acid-                                                                      40 mg     17       4                                          allylamide       80 mg     16       4                                          5-ethylsulfonyl-1,3,4-thiadia-                                                                  20 mg     13       1                                          zole-2-carboxylic acid-                                                                         40 mg     16       4                                          (2-methoxyethyl)-amide                                                                          80 mg     16       4                                          5-ethylsulfonyl-1,3,4-thia-                                                                     20 mg     11       1                                          diazole-2-carboxylic acid-                                                                      40 mg     18       4                                          (3-methoxypropyl)-amide                                                                         80 mg     17       4                                          Comparison compounds                                                           Manganese ethylene-1,2-                                                                         20 mg     1        1                                          bis-dithiocarbamate                                                                             40 mg     4        1                                                           80 mg     11       1                                          N-trichloromethylmercapto-                                                                      20 mg     1        1                                          tetrahydro-phthalimide                                                                          40 mg     2        1                                                           80 mg     8        2                                          Control I. (3 times repeated)                                                  Infested soil; no treatment                                                                     --        1        1                                                           --        0        1                                                           --        0        1                                          Control II. (3 times repeated)                                                 Humidified soil  --        18       4                                                           --        20       4                                                           --        17       4                                          ______________________________________                                    

EXAMPLE 15 Threshold concentration test in case of Fusarium avenaceum

A 20% pulverulent active agent of the type further identified in the table below was mixed in uniform manner with a soil which had been heavily infested with Fusarium avenaceum. The thus treated soil was then placed into clay dishes of a capacity of 0.5 l of earth. Each dish was seeded without any intervening time with 20 grains of garden peas (Pisum sativum L. convar. medullare Alef.) of the type "Wunder von Kelvedon". After a cultivation time of 18 days at 20° to 24° C. in a hot house the number of sound peas was determined and a root evaluation was carried out. The active agents employed, the amounts and results appear from the following table.

The root evaluation was carried out on a scale from 1 to 4 as follows:

4=white roots without fungous necroses

3=white roots with minor fungous necroses

2=brown roots already more pronounced fungous necroses `1=heavy fungous necroses with roots rotted.

    ______________________________________                                                         Concentra-       root                                                          tion of number   evalua-                                                       agent in                                                                               of sound tion                                                          mg/l soil                                                                              peas     (1-4)                                         ______________________________________                                         Active agent                                                                   5-methylsulfinyl-1,3,4-thia-                                                                     25 mg     20       4                                         diazole-2-carbonitrile                                                                           50 mg     18       4                                                           100 mg    19       4                                         5-methylsulfonyl-1,3,4-thiadia-                                                                  25 mg     18       4                                         zole-carbonitrile 50 mg     17       4                                                           100 mg    19       4                                         5-ethylsulfinyl-1,3,4-thia-                                                                      25 mg     19       4                                         diazole-2-carbonitrile                                                                           50 mg     20       4                                                           100 mg    20       4                                         5-ethylsulfonyl-1,3,4-thia-                                                                      25 mg     18       4                                         diazole-2-carbonitrile                                                                           50 mg     20       4                                                           100 mg    20       4                                         5-propylsulfinyl-1,3,4-thia-                                                                     25 mg     19       4                                         diazole-2-carbonitrile                                                                           50 mg     20       4                                                           100 mg    19       4                                         5-propylsulfonyl-1,3,4-thia-                                                                     25 mg     18       4                                         diazole-2-carbonitrile                                                                           50 mg     20       4                                                           100 mg    20       4                                         5-isopropylsulfinyl-1,3,4-thia-                                                                  25 mg     18       4                                         diazole-2-carbonitrile                                                                           50 mg     19       4                                                           100 mg    18       4                                         5-isopropylsulfonyl-1,3,4-thia-                                                                  25 mg     20       4                                         diazole-2-carbonitrile                                                                           50 mg     20       4                                                           100 mg    19       4                                         5-butylsulfinyl-1,3,4-thia-                                                                      25 mg     19       4                                         diazole-2-carbonitrile                                                                           50 mg     19       4                                                           100 mg    19       4                                         5-butylsulfonyl-1,3,4-thia-                                                                      25 mg     18       4                                         diazole-2-carbonitrile                                                                           50 mg     20       4                                                           100 mg    20       4                                         5-sec.-butylsulfonyl-1,3,4-                                                                      25 mg     20       4                                         thiadiazole-2-carbonitrile                                                                       50 mg     19       4                                                           100 mg    20       4                                         5-isobutylsulfonyl-1,3,4-                                                                        25 mg     19       4                                         thiadiazole-2-carbonitrile                                                                       50 mg     20       4                                                           100 mg    19       4                                         5-pentylsulfonyl-1,3,4-                                                                          25 mg     20       4                                         thiadiazole-2-carbonitrile                                                                       50 mg     20       4                                                           100 mg    19       4                                         5-hexylsulfonyl-1,3,4-                                                                           25 mg     19       4                                         thiadiazole-2-carbonitrile                                                                       50 mg     19       4                                                           100 mg    19       4                                         5-pentylsulfonyl-1,3,4-thia-                                                                     25 mg      9       2                                         diazole-2-carboxamide                                                                            50 mg     16       3                                                           100 mg    18       4                                         5-hexylsulfonyl-1,3,4-                                                                           25 mg      7       1                                         thiadiazole-2-carboxamide                                                                        50 mg     12       2                                                           100 mg    15       3                                         5-propylsulfonyl-1,3,4-thia-                                                                     25 mg     11       2                                         diazole-2-carboxylic acid-                                                                       50 mg     17       3                                         N,N-trimethyleneamide                                                                            100 mg    17       3                                         5-n-butylsulfonyl-1,3,4-thia-                                                                    25 mg      5       1                                         diazole-2-carboxylic acid-                                                                       50 mg     13       2                                         N,N-trimethyleneamide                                                                            100 mg    18       3                                         5-propylsulfinyl-1,3,4-thia-                                                                     25 mg      9       3                                         diazole-2-carboxylic acid-                                                                       50 mg     13       4                                         isopropylamide    100 mg    16       4                                         5-methylsulfinyl-1,3,4-thia-                                                                     25 mg      7       2                                         diazole-2-carboxylic acid-                                                                       50 mg     11       3                                         (2-chlorobenzyleamide)                                                                           100 mg    18       4                                         5-butylsulfonyl-1,3,4-                                                                           25 mg     15       2                                         thiadiazole-2-carboxamide                                                                        50 mg     12       3                                                           100 mg    16       4                                         5-propylsulfinyl-1,3,4-thia-                                                                     25 mg      9       1                                         diazole-2-carboxylic acid-                                                                       50 mg     17       4                                         sec.-butylamide   100 mg    17       4                                         5-propylsulfonyl-1,3,4-                                                                          25 mg     14       2                                         thiadiazole-2-carboxylic                                                                         50 mg     16       3                                         acid-isopropylamide                                                                              100 mg    17       4                                         5-propylsulfonyl-1,3,4-                                                                          25 mg      9       1                                         thiadiazole-2-carboxylic                                                                         50 mg     16       3                                         acid-butylamide   100 mg    17       4                                         Comparison compound:                                                           3-trichloromethyl-5-ethoxy-                                                                      25 mg      0       1                                         1,2,4-thiadiazole 50 mg      0       1                                                           100 mg     0       1                                         Manganese-ethylene-1,2,-                                                                         25 mg      0       1                                         bis-dithiocarbamate                                                                              50 mg      0       1                                                           100 mg    12       1                                         Control I. (3 times repeated)                                                  Infested soil; no treatment                                                                      --         0       1                                                           --         0       1                                                           --         0       1                                         Control II. (3 times repeated)                                                 Humidified soil   --        18       4                                                           --        20       4                                                           --        19       4                                         ______________________________________                                    

EXAMPLE 16 Inhibition of fungus in a nutrient solution

20 ml of a nutrient solution of grape juice and water (1:1) were filled into a glass vial of a 100 ml capacity and were mixed with the pulverulent active agents which appear from the subsequent table. Thereafter, the solution was inoculated with conidia (spores) of the test fungi.

After an incubation time of 6 days at 21° to 23° C. the fungus development on the surface of the nutrient solution was evaluated. The test fungi used were the following: Penicillium digitatum, Botrytis cinerea, Alternaria solani, Fusarium avenaceum.

The evaluation was carried out at a scale from 0 to 5 as follows:

0=no fungus growth;

1=isolated fungus colonies on the surface;

2=5 to 10% of the surface covered by the fungus turf;

3=10 to 30% of the surface covered by the fungus turf;

4=30 to 60% of the surface covered by the fungus turf;

5=60 to 100% of the surface covered by the fungus turf.

The active agent concentrations in the nutrient solution and the results appear from the following table.

    __________________________________________________________________________                 Concentration of                                                               agent in the                                                                            Penicillium                                                                          Botrytis                                                                            Alternaria                                                                           Fusarium                                 Active agent                                                                               nutrient solution                                                                       digitatum                                                                            cinerea                                                                             solani                                                                               avenaceum                                __________________________________________________________________________     5-methylsulfonyl-1,3-4-                                                                    0.002%   1     1    0     0                                        thiadiazole-2-carbonitrile                                                                 0.004%   0     0    0     0                                        5-ethylsulfonyl-1,3,4-                                                                     0.002%   0     1    0     0                                        thiadiazole-2-carbonitrile                                                                 0.004%   0     0    0     0                                        5-isopropylsulfonyl-1,3,4-                                                                 0.002%   0     1    0     0                                        thiadiazole-2-carbonitrile                                                                 0.004%   0     0    0     0                                        5-methylsulfonyl-1,3,4-                                                        thiadiazole-2-carboxylic                                                                   0.002%   1     1    1     0                                        acid-methylester                                                                           0.004%   0     0    0     0                                        5-ethylsulfonyl-1,3,4-                                                         thiadiazole-2-carboxylic                                                                   0.002%   1     2    0     1                                        acid-ethylester                                                                            0.004%   0     0    0     0                                        5-ethylsulfonyl-1,3,4-                                                         thiadiazole-2-carboxylic                                                                   0.002%   1     2    1     1                                        acid-butylamide                                                                            0.004%   0     0    0     0                                        5-isobutylsulfonyl-1,3,4-                                                                  0.002%   1     2    0     2                                        thiadiazole-2-                                                                 carboxamide 0.004%   0     1    0     0                                        N-trichloromethylmer-                                                                      0.002%   4     4    4     4                                        capto-phthalimide                                                                          0.004%   4     3    4     4                                        N-trichloromethylmer-                                                          capto-tetrahydro-                                                                          0.002%   4     4    4     4                                        phthalimide 0.004%   4     4    4     4                                        Tetrachloroisophthalo-                                                                     0.002%   3     5    5     4                                        dinitrile   0.004%   2     4    5     3                                        Control: untreated                                                                         --       5     5    5     5                                        nutrient solution                                                              __________________________________________________________________________

EXAMPLE 17 Threshold concentration test with root gall nematodes (Meloidogyne sp.)

20% concentration pulverulent active agents as listed in the table below were mixed in a uniform manner with a soil which had been heavily infested by root gall nematodes. After waiting for 3 days the treated soil was placed in two clay dishes of a capacity of 0.5 liter. 10 grain of cucumber seeds of the type "Guntruud" were placed into each dish.

Thereafter, the contents of the dishes were permitted to develop at a temperature of 24° to 27° C. for a time of 28 days in a hothouse. The cucumber roots were then washed out and were examined in a water bath regarding nematode infestation. The reduction of the infestation by the active agents as compared with untreated control material was determined in percentages.

The active agents amounts and reduction of infestation appear from the following table.

The nematocidal activity was calculated by the formula

    (A-B.)/A·100

In this formula

A=the infestation in the untreated control material and

B=the infestation after treatment.

    ______________________________________                                                      Percentage reduction of infestation                                            at the following agent concentra-                                              tions given in mg per liter soil                                  Active agent   200 mg    100 mg    50 mg                                       ______________________________________                                         5-methylsulfonyl-1,3,4-                                                                        96%      88%       71%                                         thiadiazole-2-carbonitrile                                                     5-methylthio-1,3,4-thia-                                                                      100%      99%       95%                                         diazole-2-carbonitrile                                                         ______________________________________                                    

EXAMPLE 18 Treatment of barley seeds infested with Helminthosporium gram

Barley seeds which all had a natural infestation by Helminthosporium gram were seeded in plant pots filled with earth and left to germination at a temperature below +16° C. Some of the seeds had not been treated, others had been treated with the active agents listed in the table. After emergence, the plants were subjected to illumination for 12 hours per day. After about 5 weeks the infested plants were counted and the total number of plants for each test were also counted. The active agents tested were used as pulverulent compositions.

The fungicidal activity was calculated as follows: ##EQU1##

    ______________________________________                                                         Amount of active                                                               agent in grams                                                                 per 100 kg % activity                                          ______________________________________                                         Active agent                                                                   5-methylsulfonyl-1,3,4-                                                                          10           95                                              thiadiazole-2-carboxamide                                                                        20           100                                                               50           100                                             5-ethylsulfonyl-1,3,4-                                                                           10           97                                              thiadiazole-2-carboxamide                                                                        20           100                                                               50           100                                             5-ethylsulfinyl-1,3,4-                                                                           10           99                                              thiadiazole-2-carboxamide                                                                        20           100                                                               50           100                                             5-isopropylsulfonyl-1,3,4-                                                                       10           --                                              thiadiazole-2-carbonitrile                                                                       20           86                                                                50           97                                              5-methylsulfonyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           99                                              acid-methylamide  50           100                                             5-methylsulfonyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           87                                              acid-dimethylamide                                                                               50           98                                              5-isobutylsulfonyl-1,3,4-                                                                        10           --                                              thiadiazole-2-carboxamide                                                                        20           60                                                                50           87                                              5-ethylsulfonyl-1,3,4-                                                                           10           --                                              thiadiazole-2-carboxylic                                                                         20           91                                              acid-methylamide  50           97                                              5-ethylsulfonyl-1,3,4-                                                                           10           --                                              thiadiazole-2-carboxylic                                                                         20           94                                              acid-dimethylamide                                                                               50           100                                             5-ethylsulfonyl-1,3,4-                                                                           10           --                                              thiadiazole-2-carboxylic                                                                         20           100                                             acid-ethylamide   50           100                                             5-ethylsulfonyl-1,3,4-                                                                           10           --                                              thiadiazole-2-carboxylic                                                                         20           --                                              acid-propylamide  50           92                                              5-ethylsulfonyl-1,3,4-                                                                           10           --                                              thiadiazole-2-carboxylic                                                                         20           100                                             acid-(N-butyl-N-methyl)-amide                                                                    50           100                                             5-ethylsulfonyl-1,3,4-                                                                           10           100                                             thiadiazole-2-carboxylic                                                                         20           99                                              acid-(2-methoxyethyl)-amide                                                                      50           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           99                                              diazole-2-carboxylic acid-                                                                       20           99                                              (3-methoxypropyl)-amide                                                                          50           100                                             5-ethylsulfonyl-1,3,4-                                                                           10           95                                              thiadiazole-2-carboxylic                                                                         20           98                                              acid-isopropyl-amide                                                                             50           100                                             5-ethylsulfonyl-1,3,4-                                                                           10           100                                             thiadiazole-2-carboxylic                                                                         20           100                                             acid-allylamide   50           100                                             5-ethylsulfonyl-1,3,4-                                                                           10           98                                              thiadiazole-2-carboxylic                                                                         20           100                                             acid-N,N-tetramethyleneamide                                                                     50           99                                              5-ethylsulfonyl-1,3,4-thia-                                                                      10           99                                              diazole-2-carboxylic acid-                                                                       20           100                                             (N,N-3-oxapentamethyleneamide)                                                                   50           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              cyclooctylamide   50           98                                              5-propylsulfinyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carbonitrile                                                                           20           87                                                                50           99                                              5-ethylsulfinyl-1,3,4-thia-                                                                      10           98                                              diazole-2-carbonitrile                                                                           20           100                                                               50           100                                             5-methylsulfonyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              ethylamide        50           93                                              5-methylsulfonyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              isopropylamide    50           90                                              5-methylsulfonyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              propylamide       50           93                                              5-methylsulfonyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              butylamide        50           90                                              5-methylsulfinyl-1,3,4-thia-                                                                     10           75                                              diazole-2-carboxylic acid-                                                                       20           98                                              propylamide       50           100                                             5-methylsulfinyl-1,3,4-thia-                                                                     10           67                                              diazole-2-carboxylic acid-                                                                       20           97                                              butylamide        50           100                                             5-sec.-butylsulfonyl-1,3,4-thia-                                                                 10           --                                              diazole-2-carboxamide                                                                            20           --                                                                50           97                                              5-methylsulfinyl-1,3,4-thia-                                                                     10           94                                              diazole-2-carboxylic acid-                                                                       20           99                                              allylamide        50           100                                             5-methylsulfonyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              allylamide        50           100                                             5-propylsulfinyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              ethylamide        50           94                                              5-propylsulfinyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              propylamide       50           94                                              5-proptlsulfinyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              allylamide        50           96                                              5-propylsulfinyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              isopropylamide    50           100                                             5-methylsulfinyl-1,3,4-thia-                                                                     10           75                                              diazole-2-carboxylic acid-                                                                       20           97                                              (2-methoxyethyl)-amide                                                                           50           100                                             5-methylsulfonyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           92                                              (2-methoxyethyl)-amide                                                                           50           100                                             5-methylsulfinyl-1,3,4-                                                                          10           98                                              thiadiazole-2-carboxylic                                                                         20           99                                              acid-ethylamide   50           100                                             5-methylsulfinyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           96                                              isopropylamide    50           100                                             5-methylsulfinyl-1,3,4-thia-                                                                     10           72                                              diazole-2-carboxylic acid-                                                                       20           98                                              cyclopropylamide  50           99                                              5-methylsulfinyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           95                                              N,N-trimethyleneamide                                                                            50           100                                             5-propylsulfonyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              dimethylamide     50           93                                              5-butylsulfinyl-1,3,4-thia-                                                                      10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              dimethylamide     50           100                                             5-propylsulfinyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              sec.-butylamide   50           94                                              5-propylsulfinyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              dimethylamide     50           100                                             5-methylsulfinyl-1,3,4-thia-                                                                     10           --                                              diadiazole-2-carbonitrile                                                                        20           --                                                                50           94                                              5-methylsulfinyl-1,3,4-thia-                                                                     10           --                                              diazole-2-carboxamide                                                                            20           --                                                                50           100                                             5-isopropylsulfinyl-1,3,4-thia-                                                                  10           --                                              diazole-2-carboxamide                                                                            20           --                                                                50           100                                             5-isopropylsulfinyl-1,3,4-thia-                                                                  10           --                                              diazole-2-carbonitrile                                                                           20           --                                                                50           93                                              Comparison compound                                                            Methoxyethyl-Hg--silicate                                                                        0.2          63                                                                0.5          91                                                                1.0          98                                              ______________________________________                                    

EXAMPLE 19 Treatment of oat seeds infested with Tilletia caries.

Oat seeds were contaminated with 3 g of the spores of the stinking smuts (bunt) (Tilletia caries) per kg of seed material. Both untreated and treated grains were then pressed with their hairy end into Petri dishes filled with moist loam and were incubated at temperatures below 12° C. for 3 days. The grains were subsequently removed and the Petri dishes were further incubated with the remaining smut spores at about 12° C. After 10 days the spores were examined regarding germination. The active agents were employed in the form of pulverulent compositions.

The fungicidal activity was calculated on the basis of the following formula: ##EQU2##

    ______________________________________                                                         Amount of active                                                               agent in grams                                                                 per 100 kg % activity                                          ______________________________________                                         Active agent                                                                   5-ethylsulfonyl-1,3,4-thia-                                                                       5           87                                              diazole-2-carboxamide                                                                            10           93                                                                20           100                                             5-ethylsulfinyl-1,3,4-thia-                                                                       5           78                                              diazole-2-carboxamide                                                                            10           96                                                                20           100                                             5-methylsulfonyl-1,3,4-thia-                                                                      5           86                                              diazole-2-carboxylic acid-                                                                       10           99                                              cyclohexyl-methylamide                                                                           20           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           100                                             diazole-2-carboxylic acid-                                                                       20           100                                             methylamide       50           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           100                                             diazole-2-carboxylic acid-                                                                       20           100                                             dimethylamide     50           100                                             5-propylsulfonyl-1,3,4-thia-                                                                     10           100                                             diazole-2-carboxamide                                                                            20           100                                                               50           100                                             5-propylsulfonyl-1,3,4-thia-                                                                     10           99.5                                            diazole-2-carboxylic acid-                                                                       20           99.5                                            methylamide       50           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           100                                             diazole-2-carboxylic acid-                                                                       20           100                                             butylamide        50           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           85                                              diazole-2-carboxylic acid-                                                                       20           100                                             cyclopropylamide  50           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           99.3                                            diazole-2-carboxylic acid-                                                                       20           100                                             ethylamide        50           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           100                                             diazole-2-carboxylic acid-                                                                       20           100                                             propylamide       50           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           98                                              diazole-2-carboxylic acid-                                                                       20           100                                             (N-butyl-N-methyl)-amide                                                                         50           100                                             5-ethylsulfonyl)-1,3,4-thia-                                                                     10           100                                             diazole-2-carboxylic acid-                                                                       20           100                                             (2-methoxyethyl)-amide                                                                           50           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           100                                             diazole-2-carboxylic acid-                                                                       20           100                                             (3-methoxypropyl)-amide                                                                          50           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           100                                             diazole-2-carboxylic acid-                                                                       20           100                                             isopropyl-amide   50           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           100                                             diazole-2-carboxylic acid-                                                                       20           100                                             allylamide        50           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           91                                              diazole-2-carboxylic acid-                                                                       20           93                                              octylamide        50           98                                              5-ethylsulfonyl-1,3,4-thia-                                                                      10           100                                             diazole-2-carboxylic acid-                                                                       20           100                                             N,N-tetramethyleneamide                                                                          50           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           --                                              diazole-2-carboxylic acid-                                                                       20           --                                              (N,N-3-oxapentamethyleneamide                                                                    50           100                                             5-ethylsulfonyl-1,3,4-thia-                                                                      10           100                                             diazole-2-carboxylic acid-                                                                       20           100                                             cyclooctylamide   50           100                                             5-propylsulfonyl-1,3,4-thia-                                                                     10           99                                              diazole-2-carbonitrile                                                                           20           100                                                               50           100                                             5-propylsulfinyl-1,3,4-thia-                                                                     10           99                                              diazole-2-carbonitrile                                                                           20           100                                                               50           100                                             5-ethylsulfinyl-1,3,4-thia-                                                                      10           99.8                                            diazole-2-carbonitrile                                                                           20           100                                                               50           100                                             5-methylsulfonyl-1,3,4-thia-                                                                     10           99.2                                            diazole-2-carboxylic acid-                                                                       20           99.2                                            ethylamide        50           98                                              5-methylsulfonyl-1,3,4-                                                                          10           100                                             thiadiazole-2-carboxylic acid-                                                                   20           100                                             isopropylamide    50           100                                             5-methylsulfonyl-1,3,4-thia-                                                                     10           99.5                                            diazole-2-carboxylic acid-                                                                       20           100                                             propylamide       50           100                                             5-methylsulfonyl-1,3,4-thia-                                                                     10           99.2                                            diazole-2-carboxylic acid-                                                                       20           100                                             butylamide        50           100                                             5-methylsulfinyl-1,3,4-                                                                          10           99                                              thiadiazole-2-carboxylic                                                                         20           100                                             acid-propylamide  50           100                                             5-methylsulfinyl-1,3,4-                                                                          10           99                                              thiadiazole-2-carboxylic                                                                         20           99.8                                            acid-butylamide   50           100                                             5-propylsulfonyl-1,3,4-                                                                          10           99.3                                            thiadiazole-2-carboxylic                                                                         20           99.8                                            acid-ethylamide   50           100                                             5-propylsulfonyl-1,3,4-                                                                          10           99.5                                            thiadiazole-2-carboxylic                                                                         20           99.7                                            acid-propylamide  50           100                                             5-propylsulfonyl-1,3,4-                                                                          10           99.3                                            thiadiazole-2-carboxylic                                                                         20           99.7                                            acid-allylamide   50           100                                             5-methylsulfinyl-1,3,4-                                                                          10           99.2                                            thiadiazole-2-carboxylic                                                                         20           100                                             acid-allylamide   50           100                                             5-sec.-butylsulfonyl-1,3,4-                                                                      10           75                                              thiadiazole-2-carbonitrile                                                                       20           91                                                                50           98                                              5-propylsulfonyl-1,3,4-                                                                          10           98                                              thiadiazole-2-carboxylic                                                                         20           99.8                                            acid-isopropylamide                                                                              50           100                                             5-propylsulfonyl-1,3,4-                                                                          10           99.2                                            thiadiazole-2-carboxylic                                                                         20           99.7                                            acid-butylamide   50           100                                             5-methylsulfonyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboyxlic                                                                         20           100                                             acid-allylamide   50           100                                             5-propylsulfinyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           99.3                                            acid-propylamide  50           100                                             5-propylsulfinyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           100                                             acid-allylamide   50           100                                             5-propylsulfinyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           100                                             acid-isopropylamide                                                                              50           100                                             5-methylsulfonyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           93                                              acid-(2-methoxyethyl)-amide                                                                      50           100                                             5-methylsulfinyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           100                                             acid-ethylamide   50           100                                             5-methylsulfinyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           100                                             acid-isopropylamide                                                                              50           100                                             5-methylsulfonyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           98                                              acid-cyclopropylamide                                                                            50           100                                             5-methylsulfinyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           98                                              acid-cyclopropylamide                                                                            50           100                                             5-methylsulfonyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           99                                              acid-N,N-trimethyleneamide                                                                       50           100                                             5-methylsulfinyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           96                                              acid-N,N-trimethyleneamide                                                                       50           100                                             5-propylsulfonyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           100                                             acid-dimethylamide                                                                               50           100                                             5-butylsulfinyl-1,3,4-                                                                           10           --                                              thiadiazole-2-carboxamide                                                                        20           95                                                                50           100                                             5-butylsulfonyl-1,3,4-                                                                           10           --                                              thiadiazole-2-carbonitrile                                                                       20           95                                                                50           100                                             5-isobutylsulfonyl-1,3,4-                                                                        10           --                                              thiadiazole-2-carbonitrile                                                                       20           93                                                                50           100                                             5-propylsulfonyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           100                                             acid-hexylamide   50           100                                             5-isopropylsulfonyl-1,3,4-                                                                       10           --                                              thiadiazole-2-carboxylic                                                                         20           92                                              acid-cyclohexylmethylamide                                                                       50           97                                              5-isopropylsulfinyl-1,3,4-                                                                       10           --                                              thiadiazole-2-carboxylic                                                                         20           99                                              acid-cyclohexylmethylamide                                                                       50           100                                             5-propylsulfinyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           100                                             acid-butylamide   50           100                                             5-propylsulfinyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           100 -acid-sec.-butylamide 50 100                5-propylsulfinyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           100                                             acid-hexylamide   50           100                                             5-propylsulfinyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           100                                             acid-dimethylamide                                                                               50           100                                             5-methylsulfinyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carbonitrile                                                                       20           100                                                               50           100                                             5-methylsulfinyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxamide                                                                        20           98                                                                50           100                                             5-isopropylsulfinyl-1,3,4-                                                                       10           --                                              thiadiazole-2-carboxamide                                                                        20           --                                                                50           100                                             5-isopropylsulfinyl-1,3,4-                                                                       10           --                                              thiadiazole-2-carbonitrole                                                                       20           87                                                                50           100                                             5-pentylsulfonyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carbonitrile                                                                       20           --                                                                50           90                                              5-hexylsulfonyl-1,3,4-                                                                           10           --                                              thiadiazole-2-carbonitrile                                                                       20           --                                                                50           90                                              5-pentylsulfonyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxamide                                                                        20           --                                                                50           80                                              5-hexylsulfonyl-1,3,4-                                                                           10           --                                              thiadiazole-2-carboxamide                                                                        20           --                                                                50           98                                              5-propylsulfonyl-1,3,4-                                                                          10           --                                              thiadiazole-2-carboxylic                                                                         20           --                                              acid-N,N-trimethyleneamide                                                                       50           100                                             5-n-butylsulfonyl-1,3,4-                                                                         10           --                                              thiadiazole-2-carboxylic                                                                         20           --                                              acid-N,N-trimethyleneamide                                                                       50           100                                             5-butylsulfinyl-1,3,4-                                                                           10           --                                              thiadiazole-2-carbonitrile                                                                       20           --                                                                50           100                                             Comparison compound                                                            methoxyethyl-Hg--silicate                                                                          1.3        90                                                                  2.6        100                                             ______________________________________                                    

EXAMPLE 20 Spray treatment of rice seedlings infested with Piricularia oryzae

Young rice plants were sprayed so as to be dripping wet with the active agent concentrations shown in the subsequent table. After drying of the spray deposits the treated plants as well as the untreated plants were inoculated by spraying of a suspension of spores (about 200000/ml) of the Piricularia oryzae (the leaf smut cause), and were incubated in moist condition at a temperature of 25° to 27° C. in a hothouse. After 5 days it was determined which percentage of the leaf surface had been affected by the infestation.

The active compounds were employed in the form of pulverulent compositions. From the infestation figures found the fungicidal activity was determined on the basis of the following formula: ##EQU3##

    ______________________________________                                                          Concentration                                                                  of active agent                                                                (percentages)                                                                            % activity                                          ______________________________________                                         Active agent                                                                   5-methylsulfonyl-1,3,4-                                                                           0.02        --                                              thiadiazole-2-carboxamide                                                                         0.1         96                                              5-methylsulfonyl-1,3,4-                                                                           0.02        60                                              thiadiazole-2-carboxylic                                                                          0.1         80                                              acid-cyclohexyl-methylamide                                                    5-isopropylsulfonyl-1,3,4-                                                                        0.02        --                                              thiadiazole-2-carboxamide                                                                         0.1         40                                              5-isopropylsulfonyl-1,3,4-                                                                        0.02        --                                              thiadiazole-2-carbonitrile                                                                        0.1         94                                              5-methylsulfonyl-1,3,4-                                                        thiadiazole-2-carboxylic                                                                          0.02        65                                              acid-methylamide   0.1         91                                              5-methylsulfonyl-1,3,4-                                                        thiadiazole-2-carboxylic                                                                          0.02        91                                              acid-dimethylamide 0.1         98                                              5-isobutylsulfonyl-1,3,4-                                                                         0.02        65                                              thiadiazole-2-carboxamide                                                                         0.1         90                                              5-ethylsulfonyl-1,3,4-                                                         thiadiazole-2-carboxylic                                                                          0.1         90                                              acid-dimethylamide                                                             5-ethylsulfonyl-1,3,4-thia-                                                    diazole-2-carboxylic acid-                                                                        0.1         97                                              butylamide                                                                     5-ethylsulfonyl-1,3,4-thia-                                                    diazole-2-carboxylic acid-                                                                        0.1         95                                              ethylester                                                                     5-ethylsulfonyl-1,3,4-thia-                                                    diazole-2-carboxylic acid-                                                                        0.1         90                                              (2-methoxyethyl)-amide                                                         5-ethylsulfonyl-1,3,4-thia-                                                    diazole-2-carboxylic acid-                                                                        0.1         97                                              (3-methoxypropyl)-amide                                                        5-ethylsulfonyl-1,3,4-thia-                                                    diazole-2-carboxylic acid-                                                                        0.1         99                                              isopropylamide                                                                 5-propylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid-                                                                        0.1         93                                              ethylester                                                                     5-propylsulfonyl-1,3,4-thia-                                                   diazole-2-carbonitrile                                                                            0.1         99.5                                            5-methylsulfonyl-1,3,4-                                                        thiadiazole-2-carboxylic                                                                          0.1         90                                              acid-ethylamide                                                                5-methylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid-                                                                        0.1         90                                              isopropylamide                                                                 5-methylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid-                                                                        0.1         90                                              propylamide                                                                    5-methylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid-                                                                        0.1         90                                              butylamide                                                                     5-propylsulfonyl-1,3,4-thiadia-                                                zole-2-carboxylic acid-                                                                           0.1         93                                              allylamide                                                                     5-sec.-butylsulfonyl-1,3,4-thia-                                               diazole-2-carbonitrile                                                                            0.1         99.5                                            5-propylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid-                                                                        0.1         90                                              isopropylamide                                                                 5-methylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid-                                                                        0.1         94                                              allylamide                                                                     5-propylsulfinyl-1,3,4-thia-                                                   diazole-2-carboxylic acid-                                                                        0.1         90                                              ethylamide                                                                     5-propylsulfinyl-1,3,4-thia-                                                   diazole-2-carboxylic acid-                                                                        0.1         93                                              propylamide                                                                    5-methylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid-                                                                        0.1         90                                              (3-methoxypropyl)-amide                                                        5-methylsulfinyl-1,3,4-thia-                                                   diazole-2-carboxylic acid-                                                                        0.1         90                                              ethylamide                                                                     5-methylsulfinyl-1,3,4-thia-                                                   diazole-2-carboxylic acid-                                                                        0.1         90                                              isopropylamide                                                                 5-propylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid-                                                                        0.1         93                                              dimethylamide                                                                  5-butylsulfinyl-1,3,4-thia-                                                    diazole-2-carboxamide                                                                             0.1         93                                              5-isobutylsulfonyl-1,3,4-thia-                                                 diazole-2-carbonitrile                                                                            0.1         100                                             5-propylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid-                                                                        0.1         95                                              hexylamide                                                                     5-isopropylsulfonyl-1,3,4-thia-                                                diazole-2-carboxylic acid-                                                                        0.1         98                                              cyclohexylmethylamide                                                          Comparison compound                                                            "Blasticidin-S" (antibiotic from                                                                  0.02        90                                              Streptomyces griseochromogenes)                                                                   0.1         97                                              ______________________________________                                    

EXAMPLE 21 Seed treatment in open field tests regarding infestation by Tilletia caries

1 kg of oat seeds each was contaminated with 5 g of spores of the cause of the stinking smuts disease, Tilletia caries. Part of the seeds was then treated with the active agents listed below in the table and another part was untreated. All the seeds were then planted in open fields.

The active agents were employed in the form of pulverulent compositions. After about 9 months in case of winter oats and after about 4 months in case of summer oats the diseased heads were counted and on that basis the activity was calculated by the following formula: ##EQU4##

    ______________________________________                                                        g active agent/                                                                100 kg     % activity                                           ______________________________________                                         Active agent     winter oats                                                   5-methylsulfonyl-1,3,4-                                                                         25           100                                              thiadiazole-2-carboxamide                                                                       50           100                                                               100          100                                              5-methylsulfonyl-1,3,4-thia-                                                                    25           --                                               diazole-2-carboxylic acid-                                                                      50           --                                               cyclohexyl-methylamide                                                                          100          100                                              5-isopropylsulfonyl-1,3,4-                                                                      25           --                                               thiadiazole-2-carbonitrile                                                                      50           --                                                                100          100                                              Comparison compound                                                            Methoxyethyl-Hg--silicate                                                                       5.3           99                                              Untreated 7.1% infestation                                                                      summer oats                                                   5-ethylsulfinyl-1,3,4-thia-                                                                     25           100                                              diazole-2-carboxamide                                                                           50           100                                              5-methylsulfonyl-1,3,4-                                                                         25           --                                               thiadiazole-2-carboxylic                                                                        50           100                                              acid-methylamide                                                               5-isobutylsulfonyl-1,3,4-                                                                       25           --                                               thiadiazole-2-carboxamide                                                                       50            99                                              Comparison compound                                                            Methoxyethyl-Hg--silicate                                                                       2.6           99                                              Untreated 34.5% infestation                                                    ______________________________________                                    

EXAMPLE 22 Seed treatment in open field tests for infestation by Helminthosporium gramineum

Barley seeds which had a natural infestation of Helminthosporium gramineum which causes the streak disease were seeded in open fields. Part of the seeds had been treated with the active agents listed in the table below and another part had been left untreated.

The active agents were used in the form of pulverulent compositions. After about 8 months in case of winter barley and after about 3 months in case of summer barley the infested plants were counted and the activity was calculated by the formula ##EQU5##

    ______________________________________                                                          g active agent/                                                                100 kg barley                                                                            % activity                                          ______________________________________                                         Active agent       Winter barley                                               5-methylsulfonyl-1,3,4-thia-                                                                      25          90                                              diazole-2-carboxamide                                                                             50          96                                                                 75          100                                                                100         100                                             5-isopropylsulfonyl-1,3,4-                                                                        25          --                                              thiadiazole-2-carbonitrile                                                                        50          --                                                                 75          99                                                                 100         100                                             5-methylsulfonyl-1,3,4-thia-                                                                      25          99.5                                            diazole-2-carboxylic acid-                                                                        50          99.5                                            methylamide        75          100                                             5-methylsulfonyl-1,3,4-thia-                                                                      25          --                                              diazole-2-carboxylic acid-                                                                        50          98                                              dimethylamide      75          --                                                                 100         100                                             5-isobutylsulfonyl-1,3,4-                                                                         25          --                                              thiadiazole-2-carboxamide                                                                         50          100                                                                75          100                                                                100         100                                             5-ethylsulfonyl-1,3,4-thia-                                                                       25          --                                              diazole-2-carboxylic acid-                                                                        50          100                                             methylamide        75          --                                                                 100         100                                             5-ethylsulfonyl-1,3,4-thia-                                                                       25          --                                              diazole-2-carboxylic acid-                                                                        50          99.5                                            dimethylamide      75          --                                                                 100         100                                             Comparison compound                                                            Methoxyethyl-Hg--silicate                                                                         5.2         100                                                                2.6         99.4                                            Untreated 11.2% infestation                                                                       Summer barley                                               5-methylsulfonyl-1,3,4-                                                                           25          95                                              thiadiazole-2-carboxamide                                                                         50          100                                                                100         100                                             5-isopropylsulfonyl-1,3,4-                                                                        25          100                                             thiadiazole-2-carbonitrile                                                                        50          99.8                                                               100         100                                             5-methylsulfonyl-1,3,4-                                                                           25          93                                              thiadiazole-2-carboxylic                                                                          50          100                                             acid-methylamide   100         100                                             5-isobutylsulfonyl-1,3,4-                                                                         25          --                                              thiadiazole-2-carboxamide                                                                         50          99.5                                                               100         100                                             5-ethylsulfonyl-1,3,4-thia-                                                                       25          --                                              diazole-2-carboxylic acid-                                                                        50          100                                             methylamide        100         100                                             5-ethylsulfonyl-1,3,4-thia-                                                                       25          --                                              diazole-2-carboxylic acid-                                                                        50          99.5                                            dimethylamide      100         100                                             5-ethylsulfonyl-1,3,4-thia-                                                                       25          --                                              diazole-2-carboxylic acid-                                                                        50          --                                              butylamide         100         100                                             5-ethylsulfonyl-1,3,4-thia-                                                                       25          --                                              diazole-2-carboxylic acid-                                                                        50          --                                              cyclopropylamide   200         100                                             5-ethylsulfonyl-1,3,4-thia-                                                                       25          98                                              diazole-2-carboxylic acid-                                                                        50          99.5                                            ethylamide         100         100                                             5-ethylsulfonyl-1,3,4-thia-                                                                       25          95                                              diazole-2-carboxylic acid-                                                                        50          99.3                                            propylamide        100         100                                             5-ethylsulfonyl-1,3,4-thia-                                                                       25          94                                              diazole-2-carboxylic acid-                                                                        50          96.9                                            (N-butyl-N-methyl)-amide                                                                          100         99.5                                            5-ethylsulfonyl-1,3,4-thia-                                                                       25          92                                              diazole-2-carboxylic acid-                                                                        50          98                                              (2-methoxyethyl)-amide                                                                            100         99.8                                            5-ethylsulfonyl-1,3,4-thia-                                                                       25          94                                              diazole-2-carboxylic acid-                                                                        50          96                                              (3-methoxypropyl)-amide                                                                           100         100                                             5-ethylsulfonyl-1,3,4-thia-                                                                       25          96                                              diazole-2-carboxylic acid-                                                                        50          100                                             isopropyl-amide    100         99.8                                            5-ethylsulfonyl-1,3,4-thia-                                                                       25          97                                              diazole-2-carboxylic acid-                                                                        50          100                                             allylamide         100         100                                             5-ethylsulfonyl-1,3,4-thia-                                                                       25          --                                              diazole-2-carboxylic acid-                                                                        50          100                                             N,N-tetramethyleneamide                                                                           100         --                                              5-ethylsulfonyl-1,3,4-thia-                                                                       25          --                                              diazole-2-carboxylic acid-                                                                        50          99.3                                            (N,N-3-oxapentamethyleneamide)                                                                    100         --                                              5-propylsulfinyl-1,3,4-thia-                                                                      25          --                                              diazole-2-carbonitrile                                                                            50          99.3                                                               100         --                                              5-ethylsulfinyl-1,3,4-thia-                                                                       25          --                                              diazole-2-carbonitrile                                                                            50          100                                                                100         --                                              5-methylsulfonyl-1,3,4-thia-                                                                      25          --                                              diazole-2-carboxylic acid-                                                                        50          100                                             ethylamide         100         --                                              5-methylsulfonyl-1,3,4-thia-                                                                      25          --                                              diazole-2-carboxylic acid-                                                                        50          100                                             isopropylamide     100         --                                              5-methylsulfonyl-1,3,4-thia-                                                                      25          --                                              diazole-2-carboxylic acid-                                                                        50          100                                             propylamide        100         --                                              5-methylsulfonyl-1,3,4-thia-                                                                      25          --                                              diazole-2-carboxylic acid-                                                                        50          99.3                                            butylamide         100         --                                              5-methylsulfinyl-1,3,4-thia-                                                                      25          --                                              diazole-2-carboxylic acid-                                                                        50          97                                              propylamide        100         --                                              5-methylsulfinyl-1,3,4-thia-                                                                      25          --                                              diazole-2-carboxylic acid-                                                                        50          100                                             butylamide         100         --                                              5-sec.-butylsulfonyl-1,3,4-                                                                       25          --                                              thiadiazole-2-carboxyamide                                                                        50          94                                                                 100         --                                              5-methylsulfinyl-1,3,4-thia-                                                                      25          --                                              diazole-2-carboxylic acid-                                                                        50          100                                             allylamide         100         --                                              Comparison compound                                                            Methoxyethyl-Hg--silicate                                                                         10.4        100                                                                5.2         99.8                                            Untreated 23.9% infestation                                                    ______________________________________                                    

EXAMPLE 23 Oat seed treatment for Ustilago avenae

Oat seeds were dipped into a suspension of the spores of Ustilago avenae which causes the oat smuts fungus. The seeds were then exposed in a vacuum desiccator several times to a change from atmospheric to subatmospheric pressure. After drying the seeds were treated with the active agents listed in the subsequent table. These agents were used in the form of pulverulent compositions. 10 weeks after seeding the diseased pancicles were counted and on this basis the activity was calculated by the formula ##EQU6##

    ______________________________________                                                       g active agent/                                                                100 kg     % activity                                            ______________________________________                                         Active agent                                                                   5-methylsulfonyl-1,3,4-thia-                                                                   100          84                                                diazole-2-carboxamide                                                                          150          90                                                5-isopropylsulfonyl-1,3,4-                                                                     100          97                                                thiadiazole-2-carbonitrile                                                                     150          --                                                5-methylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid-                                                                     100          90                                                methylamide     150          --                                                5-isobutylsulfonyl-1,3,4-                                                                      100          87                                                thiadiazole-2-carboxamide                                                                      150          --                                                Comparison compound                                                            Methoxyethyl-Hg--silicate                                                                       16          66                                                Untreated 16.6% infestation                                                    ______________________________________                                    

EXAMPLE 24 Effects of prophylactic leaf treatment of grapevines in the hothouse against Plasmopara viticola

Young grapevine plants having from 5 to 8 leaves were sprayed dripping wet with the concentrations of active agents stated in the table below. After drying of the spray deposit the leaves were sprayed with an aqueous suspension of sporangia of the fungus (about 20,000 per ml); the spraying was applied to the bottom side of the leaves. The plants were then immediately incubated in a hothouse at a temperature of 22° to 24° C. and at maximum water saturation in the atmosphere. Beginning with the second day the humidity of the air was reduced for 3 to 4 days to normal level (30 to 70% saturation) and was then maintained for another day on the level of full saturation. Subsequently, the percentage portion of the fungus infested surface of each leaf was noted and the average per treatment was calculated in order to determine the fungicidal activity. This was done on the basis of the following formula: ##EQU7##

The active compounds were applied in the form of a 20% concentration spray powder.

    ______________________________________                                                          Concentration                                                 Active agent     of active agent                                                                            % activity                                        ______________________________________                                         5-methylsulfonyl-1,3,4-thia-                                                                    0.001       76                                                diazole-2-carboxylic acid                                                                       0.005       88                                                hexahydrobenzylamide                                                                            0.025       97                                                5-propylsulfonyl-1,3,4-                                                                         0.001       --                                                thiadiazole-2-carboxamide                                                                       0.005       89                                                                 0.025       95                                                5-ethylsulfonyl-1,3,4-thia-                                                                     0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       --                                                ethylamide       0.025       98                                                5-ethylsulfonyl-1,3,4-thia-                                                                     0.001       100                                               diazole-2-carboxylic acid-                                                                      0.005       100                                               (N-butyl-N-methyl)-amide                                                                        0.025       100                                               5-ethylsulfonyl-1,3,4-thia-                                                                     0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       --                                                (3-methoxypropyl)-amide                                                                         0.025       90                                                5-ethylsulfonyl-1,3,4-thia-                                                                     0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       --                                                isopropyl-amide  0.025       92                                                5-ethylsulfonyl-1,3,4-thia-                                                                     0.001       98                                                diazole-2-carboxylic acid-                                                                      0.005       96                                                allylamide       0.025         99.4                                            5-ethylsulfonyl-1,3,4-thia-                                                                     0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       --                                                octylamide       0.025       90                                                5-ethylsulfonyl-1,3,4-thia-                                                                     0.001       91                                                diazole-2-carboxylic acid-                                                                      0.005       99                                                N,N-tetramethyleneamide                                                                         0.025       100                                               5-propylsulfinyl-1,3,4-                                                                         0.001       100                                               thiadiazole-2-carbonitrile                                                                      0.005       100                                                                0.025       100                                               5-ethylsulfinyl-1,3,4-                                                                          0.001       89                                                thiadiazole-2-carbonitrile                                                                      0.005       96                                                                 0.025       100                                               5-methylsulfonyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       81                                                ethylamide       0.025       97                                                5-methylsulfonyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       76                                                isopropylamide   0.025       96                                                5-methylsulfonyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       82                                                propylamide      0.025       95                                                5-methylsulfonyl-1,3,4-thia                                                                     0.001       83                                                diazole-2-carboxylic acid-                                                                      0.005         99.1                                            butylamide       0.025         99.2                                            5-methylsulfinyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       75                                                propylamide      0.025       99                                                5-methylsulfinyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       --                                                butylamide       0.025       93                                                5-propylsulfonyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       --                                                propylamide      0.025       93                                                5-methylsulfinyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       --                                                allylamide       0.025       90                                                5-methylsulfinyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       --                                                (2-methoxyethyl)-amide                                                                          0.025       96                                                5-methylsulfinyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       --                                                ethylamide       0.025       96                                                5-methylsulfinyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       --                                                isopropylamide   0.025       90                                                5-methylsulfinyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       80                                                cyclopropylamide 0.025       90                                                5-methylsulfonyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       84                                                N,N-trimethyleneamide                                                                           0.025       90                                                5-methylsulfinyl-1,3,4-thia-                                                                    0.001       86                                                diazole-2-carboxylic acid-                                                                      0.005       93                                                N,N-trimethyleneamide                                                                           0.025       94                                                5-propylsulfonyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       75                                                dimethylamide    0.025       90                                                5-butylsulfonyl-,3,4-thia-                                                                      0.001       --                                                diazole-2-carboxaimide                                                                          0.005       73                                                                 0.025       90                                                5-butylsulfinyl-1,3,4-thia-                                                                     0.001       75                                                diazole-2-carboxamide                                                                           0.005         99.8                                                             0.025       100                                               5-butylsulfonyl-1,3,4-thia-                                                                     0.001       --                                                diazole-2-carbonitrile                                                                          0.005       91                                                                 0.025       93                                                5-isobutylsulfonyl-1,3,4-thia-                                                                  0.001       79                                                diazole-2-carbonitrile                                                                          0.005       87                                                                 0.025       99                                                5-propylsulfonyl-1,3,4-thia-                                                                    0.001       88                                                diazole-2-carboxylic acid-                                                                      0.005       98                                                hexylamide       0.025       100                                               5-isopropylsulfonyl-1,3,4-thia-                                                                 0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       92                                                cyclohexylmethylamide                                                                           0.025       97                                                5-propylsulfinyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carboxylic acid-                                                                      0.005       91                                                butylamide       0.025         99.1                                            5-propylsulfinyl-1,3,4-thia-                                                                    0.001       86                                                diazole-2-carboxylic acid-                                                                      0.005       92                                                sec.-butylamide  0.025       92                                                5-propylsulfinyl-1,3,4-thia-                                                                    0.001       95                                                diazole-2-carboxylic acid-                                                                      0.005         99.1                                            hexylamide       0.025       100                                               5-pentylsulfonyl-1,3,4-thia-                                                                    0.001       --                                                diazole-2-carbonitrile                                                                          0.005       --                                                                 0.025       90                                                5-hexylsulfonyl-1,3,4-                                                                          0.001       --                                                thiadiazole-2-carbonitrile                                                                      0.005       --                                                                 0.025       90                                                5-hexylsulfonyl-1,3,4-                                                                          0.001       --                                                thiadiazole-2-carboxamide                                                                       0.005       --                                                                 0.025       90                                                ______________________________________                                    

EXAMPLE 25 Effects of a prophylactic leaf treatment of tomato plants against Botrytis cinerea

Young tomato plants were sprayed dripping wet with the concentrations of the active agents as indicated in the subsequent table. After drying of the spray deposit the treated plants and also untreated control plants were inoculated by spraying with a suspension of spores (about 1 million per ml of fruit juice solution) of Botrytis cinerea and were incubated in moist condition in a hothouse at about 20° C. After the collapse of the untreated plants (indicating 100% infestation) the degree of infestation of the treated plants was determined and the fungicidal activity was calculated on the basis of the following formula ##EQU8##

The active agents were applied in the form of 20% concentration spray powders.

    ______________________________________                                                               % activity at a con-                                                           centration of 0.025                                      Active agent          of the active agent                                      ______________________________________                                         5-methylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-methylamide                                                                        78                                                       5-propylsulfonyl-1,3,4-thiadiazole-                                            2-carboxyamide        94                                                       5-propylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-methylamide                                                                        88                                                       5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid-octylamide                                                                         87                                                       5-ethylsulfonyl-1,3,4-thiadiazole-2                                            carboxylic acid-N,N-tetramethyleneamide                                                              75                                                       5-ethylsulfonyl-1,3,4-thiadiazole-2-                                           carboxylic acid-cyclooctylamide                                                                      93                                                       5-methylsulfonyl-1,3,4-thiadiazole-2-                                          carboxylic acid-propylamide                                                                          76                                                       5-methylsulfonyl-1,3,4-thiadiazole-2-                                          carboxylic acid-butylamide                                                                           76                                                       5-propylsulfonyl-1,3,4-thiadiazole-2-                                          carboxylic acid-propylamide                                                                          80                                                       5-methylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-ethylamide                                                                           75                                                       5-methysulfonyl-1,3,4-thiadiazole-2-                                           carboxylic acid-cyclopropylamide                                                                     75                                                       5-propylsulfonyl-1,3,4-thiadiazole-2-                                          carboxylic acid-hexylamide                                                                           78                                                       5-propylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-butylamide                                                                           80                                                       5-propylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-sec.-butylamide                                                                      80                                                       5-propylsulfinyl-1,3,4-thiadiazole-2-                                          carboxylic acid-hexylamide                                                                           80                                                       5-propylsulfinyl-1,3,4-thiadiazole-                                            2-carboxylic acid-dimethylamide                                                                      80                                                       5-pentylsulfonyl-1,3,4-thiadiazole-                                            2-carbonitrile        86                                                       5-hexylsulfonyl-1,3,4-thiadiazole-                                             2-carbonitrile        86                                                       5-pentylsulfonyl-1,3,4-thiadiazole-                                            2-carboxamide         87                                                       5-hexylsulfonyl-1,3,4-thiadiazole-                                             2-carboxamide         87                                                       5-propylsulfonyl-1,3,4-thiadiazole-                                            2-carboxylic acid-N,N-trimethylene-                                            amide                 87                                                       ______________________________________                                    

EXAMPLE 26 Treatment of rye seeds against Fusarium nivale

Rye seeds with a natural infestation by Fusarium nivale were seeded in earth filled pots and left for germination at about 6° C. Part of the seeds was treated before seeding with the active agents as appears from the subsequent table and part was untreated. After emergence of the seedlings the plants were illuminated with artificial light for 12 hours each day. After about 4 weeks the degree of infestation was determined in percentages. The fungicidal activity was calculated on the basis of the following formula: ##EQU9##

The active agents were used in the form of 20% concentration compositions.

    ______________________________________                                                              % activity; amount                                                             of active agent:                                          Active agent         100 g/100 kg                                              ______________________________________                                         5-methylsulfonyl-1,3,4-                                                        thiadiazole-2-carboxamide                                                                           99                                                        5-ethylsulfonyl-1,3,4-                                                         thiadiazole-2-carboxamide                                                                           99.2                                                      5-ethylsulfonyl-1,3,4-                                                         thiadiazole-2-carbonitrile                                                                          92                                                        5-ethylsulfinyl-1,3,4-                                                         thiadiazole-2-carboxamide                                                                           93                                                        5-methylsulfonyl-1,3,4-                                                        thiadiazole-2-carboxylic                                                       acid-methylamide     100                                                       5-isobutylsulfonyl-1,3,4-                                                      thiadiazole-2-carboxamide                                                                           99.2                                                      5-ethylsulfonyl-1,3,4-                                                         thiadiazole-2-carboxylic                                                       acid-methylamide     100                                                       5-ethylsulfonyl-1,3,4-thia-                                                    diazole-2-carboxylic acid-                                                     dimethylamide        100                                                       5-ethylsulfonyl-1,3,4-thia-                                                    diazole-2-carboxylic acid-                                                     allylamide           94                                                        ______________________________________                                    

EXAMPLE 27 Effects of the treatment of oat seeds against Septoria nodorum

Oat seeds with a natural infestation by Septoria nodorum were treated with the active agents as indicated in the table below. They were then seeded on a moist substrate for germination. As a control untreated seeds were likewise seeded. At about 6° C. the seed was incubated in an air-conditioned chamber until after 4 weeks the proportion of diseased seeds could be determined and the activity of the fungicidal compounds was calculated on the basis of the following formula: ##EQU10##

The active agents were applied in the form of 20% concentration pulverulent compositions.

    ______________________________________                                                                % activity in case of                                                          50 g active agent/                                                             100 kg seeds                                            ______________________________________                                         Active agent                                                                   5-methylsulfonyl-1,3,4-                                                        thiadiazole-2-carboxamide                                                                             91                                                      5-methylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid                                                      methylamide            93                                                      5-ethylsulfonyl-1,3,4-thia-                                                    diazole-2-carboxylic acid                                                      methylamide            72                                                      5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid dimethylamide                                                                       86                                                      5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid propylamide                                                                         81                                                      5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid (2-methoxyethyl)-amide                                                              86                                                      5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid (3-methoxypropyl)-                                           amide                  86                                                      5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid isopropylamide                                                                      86                                                      5-ethylsulfonyl-1,3,4-thiadiazole-                                             2-carboxylic acid allylamide                                                                          72                                                      Comparison compound                                                                            1.3 g active agent/100 kg seeds                                Methoxyethyl-Hg-silicate                                                                       86                                                             Untreated      75% infested                                                    ______________________________________                                    

EXAMPLE 28 Prophylactic leaf treatment of apples in open field test against Venturia inaequalis

Apple shoots with young leaves were treated with the agents stated in the subsequent table until they were dripping wet. After drying of the spray deposits these shoots and also untreated shoots were inoculated by uniform spraying with a suspension of conidia spores of Venturia inaequalis in a 3% aqueous glucose solution (400,000 spores/ml).

Subsequently, each apple shoot was covered with a polyethylene bag so as to obtain favorable conditions for the infection. After more than 48 hours the bags were removed. The scab infestation of the leaves was determined after 3 weeks by estimating the degree of scab coverage in percentage of each leaf surface. The activity of the fungicidal agent was calculated on this basis by the following formula: ##EQU11##

The active agents were employed as a 50% concentration spray powder.

    ______________________________________                                                        Concentration                                                                  of active agent                                                                in gram    % activity                                           ______________________________________                                         Active agent                                                                   5-isopropylsulfonyl-1,3,4-                                                     thiadiazole-2-carbonitrole                                                                      0.005        97                                                                0.025        100                                              5-methylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid                                                                       0.005        90                                               methylamide      0.025        92                                               5-isobutylsulfonyl-1,3,4-thia-                                                                  0.005        87                                               diazole-2-carboxamide                                                                           0.025        95                                               5-methylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid                                                                       0.005        81                                               ethylamide       0.025        97                                               5-methylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid                                                                       0.005        85                                               isopropylamide   0.025        100                                              5-methylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid                                                                       0.005        98                                               propylamide      0.025        99.7                                             5-methylsulfonyl-1,3,4-thia-                                                   diazole-2-carboxylic acid                                                                       0.005        94                                               butylamide       0.025        99                                               5-methylsulfinyl-1,3,4-thia-                                                   diazole-2-carboxylic acid                                                                       0.005        62                                               propylamide      0.025        99.7                                             5-methylsulfinyl-1,3,4-thia-                                                   diazole-2-carboxylic acid                                                                       0.005        86                                               butylamide       0.025        99                                               5-methylsulfinyl-1,3,4-thia-                                                   diazole-2-carboxylic acid                                                                       0.005        71                                               isopropylamide   0.025        90                                               Comparison compound                                                            2,3-dinitrilo-1,4-anthraquinone                                                                 0.005        86                                                                0.025        94                                               Untreated        96% infestation                                               ______________________________________                                    

EXAMPLE 29 Treatment of wheat and barley seeds in open field tests against Ustilago nuda

Winter wheat seeds which had been infested with the smut cause Ustilago nuda tritici and winter barley seeds infested with Ustilago nuda nuda were treated with the agents listed in the table below and were seeded at seeding time in open fields. As a control untreated seeds were likewise included in the seed. After eight months the affected heads were counted for each test group and their proportion was calculated in order to find the fungicidal activity by the following formula: ##EQU12##

The active compounds were employed in the form of 20% concentration powder compositions.

    ______________________________________                                                     amount of                                                                      active agent                                                                              % activity                                                            in gram/100 kg                                                                              winter   winter                                     Active agent  seeds        oats     barley                                     ______________________________________                                         5-isopropylsulfonyl-                                                           1,3,4-thiadiazole-2-                                                           carbonitrile  100          70       93                                         5-isobutylsulfonyl-                                                            1,3,4-thiadiazole-2-                                                           carboxamide   100          75       79                                         Untreated                  4.33%    1.34%                                      ______________________________________                                    

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. 

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.
 1. 1,3,4-thiadiazole-2-carboxylic acid derivatives of the formula ##STR7## wherein R is C₁ -C₆ -alkyl, C₂ -C₆ -alkenyl, C₂ -C₆ -alkinyl or C₃ -C₆ -cycloalkyl,R₁ is C₁ -C₆ -alkoxycarbonyl, aminocarbonyl, C₁ -C₈ -alkylaminocarbonyl, C₃ -C₆ -cycloalkylaminocarbonyl, di-C₁ -C₈ -alkylaminocarbonyl, cyclohexylmethylaminocarbonyl, methoxy-C₂ -C₃ -alkylaminocarbonyl, morpholinocarbonyl, pyrrolidinocarbonyl, piperidinocarbonyl or cyano, and n is 0,1 or
 2. 2. 1,3,4-thiadiazole-2-carboxylic acid derivatives of the formula ##STR8## wherein R is C₁ -C₆ -alkyl, C₂ -C₆ -alkenyl, C₂ -C₆ -alkinyl or C₃ -C₆ -cycloalkyl,R₁ is allylaminocarbonyl, N,N-trimethylene aminocarbonyl or cyclooctylaminocarbonyl and n is 0,1 or
 2. 3. The compound as defined in claim 1 which is 5-ethylsulfinyl-1,3,4-thiadiazole-2-carboxamide.
 4. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxamide.
 5. The compound as defined in claim 1 which is 5-isopropylsulfonyl-1,3,4-thiadiazole-2-carboxamide.
 6. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carbonitrile.
 7. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylester.
 8. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid cyclohexylmethylamide.
 9. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxamide.
 10. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carbonitrile.
 11. The compound as defined in claim 1 which is 5-isopropylsulfonyl-1,3,4-thiadiazole-2-carbonitrile.
 12. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid methylamide.
 13. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid dimethylamide.
 14. The compound as defined in claim 1 which is 5-isobutylsulfonyl-1,3,4-thiadiazole-2-carboxamide.
 15. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid methylamide.
 16. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid dimethylamide.
 17. The compound as defined in claim 1 which is 5-propylsulfonyl-1,3,4-thiadiazole-2-carboxamide.
 18. The compound as defined in claim 1 which is 5-propylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid methylamide.
 19. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid butylamide.
 20. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylester.
 21. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid cyclopropylamide.
 22. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid methylester.
 23. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid propylamide.
 24. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid (N-butyl, N-methyl)-amide.
 25. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid (2-methoxyethyl)-amide.
 26. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid (3-methoxypropyl)-amide.
 27. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 28. The compound as defined in claim 1 which is 5-methylthio-1,3,4-thiadiazole-2-carbonitrile.
 29. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid allylamide.
 30. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid octylamide.
 31. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid-N,N-tetramethyleneamide.
 32. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid (N,N-3-oxapentamethyleneamide).
 33. The compound as defined in claim 2 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid cyclooctylamide.
 34. The compound as defined in claim 1 which is 5-propylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylester.
 35. The compound as defined in claim 1 which is 5-propylsulfonyl-1,3,4-thiadiazole-2-carbonitrile.
 36. The compound as defined in claim 1 which is 5-propylsulfinyl-1,3,4-thiadiazole-2-carbonitrile.
 37. The compound as defined in claim 1 which is 5-ethylsulfinyl-1,3,4-thiadiazole-2-carbonitrile.
 38. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 39. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 40. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid propylamide.
 41. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid butylamide.
 42. The compound as defined in claim 1 which is 5-methylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid propylamide.
 43. The compound as defined in claim 1 which is 5-methylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid butylamide.
 44. The compound as defined in claim 1 which is 5-propylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 45. The compound as defined in claim 1 which is 5-propylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid propylamide.
 46. The compound as defined in claim 2 which is 5-propylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid allylamide.
 47. The compound as defined in claim 1 which is 5-sec.-butylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylester.
 48. The compound as defined in claim 1 which is 5-sec.-butylsulfonyl-1,3,4-thiadiazole-2-carboxamide.
 49. The compound as defined in claim 2 which is 5-methylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid allylamide.
 50. The compound as defined in claim 1 which is 5-sec.-butylsulfinyl-1,3,4-thiadiazole-2-carboxamide.
 51. The compound as defined in claim 1 which is 5-sec.-butylsulfonyl-1,3,4-thiadiazole-2-carbonitrile.
 52. The compound as defined in claim 1 which is 5-propylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 53. The compound as defined in claim 1 which is 5-propylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid butylamide.
 54. The compound as defined in claim 2 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid allylamide.
 55. The compound as defined in claim 1 which is 5-propylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 56. The compound as defined in claim 1 which is 5-propylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid propylamide.
 57. The compound as defined in claim 2 which is 5-propylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid allylamide.
 58. The compound as defined in claim 1 which is 5-propylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 59. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid (2-methoxyethyl)-amide.
 60. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid (2-methoxyethyl)-amide.
 61. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid (3-methoxypropyl)-amide.
 62. The compound as defined in claim 1 which is 5-methylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid (3-methoxypropyl)-amide.
 63. The compound as defined in claim 1 which is 5-methylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 64. The compound as defined in claim 1 which is 5-methylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 65. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid cyclopropylamide.
 66. The compound as defined in claim 1 which is 5-methylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid cyclopropylamide.
 67. The compound as defined in claim 2 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid N,N-trimethyleneamide.
 68. The compound as defined in claim 2 which is 5-methylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid N,N-trimethyleneamide.
 69. The compound as defined in claim 1 which is 5-propylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid sec.-butylamide.
 70. The compound as defined in claim 1 which is 5-propylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid dimethylamide.
 71. The compound as defined in claim 1 which is 5-butylsulfonyl-1,3,4-thiadiazole-2-carboxamide.
 72. The compound as defined in claim 1 which is 5-butylsulfinyl-1,3,4-thiadiazole-2-carboxamide.
 73. The compound as defined in claim 1 which is 5-butylsulfonyl-1,3,4-thiadiazole-2-carbonitrile.
 74. The compound as defined in claim 1 which is 5-isobutylsulfonyl-1,3,4-thiadiazole-2-carbonitrile.
 75. The compound as defined in claim 1 which is 5-propylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid hexylamide.
 76. The compound as defined in claim 1 which is 5-isopropylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid cyclohexylmethylamide.
 77. The compound as defined in claim 1 which is 5-isopropylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid cyclohexylmethylamide.
 78. The compound as defined in claim 1 which is 5-propylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid butylamide.
 79. The compound as defined in claim 1 which is 5-propylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid sec.-butylamide.
 80. The compound as defined in claim 1 which is 5-propylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid hexylamide.
 81. The compound as defined in claim 1 which is 5-propylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid dimethylamide.
 82. The compound as defined in claim 1 which is 5-methylsulfinyl-1,3,4-thiadiazole-2-carbonitrile.
 83. The compound as defined in claim 1 which is 5-methylsulfinyl-1,3,4-thiadiazole-2-carboxyamide.
 84. The compound as defined in claim 1 which is 5-isopropylsulfinyl-1,3,4-thiadiazole-2-carboxamide.
 85. The compound as defined in claim 1 which is 5-isopropylsulfinyl-1,3,4-thiadiazole-2-carbonitrile.
 86. The compound as defined in claim 1 which is 5-pentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylester.
 87. The compound as defined in claim 1 which is 5-pentylsulfonyl-1,3,4-thiadiazole-2-carbonitrile.
 88. The compound as defined in claim 1 which is 5-hexylsulfonyl-1,3,4-thiadiazole-2-carbonitrile.
 89. The compound as defined in claim 1 which is 5-pentylsulfonyl-1,3,4-thiadiazole-2-carboxamide.
 90. The compound as defined in claim 1 which is 5-hexylsulfonyl-1,3,4-thiadiazole-2-carboxamide.
 91. The compound as defined in claim 2 which is 5-propylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid N,N-trimethyleneamide.
 92. The compound as defined in claim 2 which is 5-butylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid N,N-trimethyleneamide.
 93. The compound as defined in claim 1 which is 5-butylsulfinyl-1,3,4-thiadiazole-2-carbonitrile.
 94. The compound as defined in claim 2 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid N,N-trimethyleneamide.
 95. The compound as defined in claim 1 which is 5-isopropylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid methylamide.
 96. The compound as defined in claim 1 which is 5-isopropylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 97. The compound as defined in claim 1 which is 5-isopropylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 98. The compound as defined in claim 1 which is 5-isopropylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid propylamide.
 99. The compound as defined in claim 1 which is 5-isopropylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid butylamide.
 100. The compound as defined in claim 1 which is 5-isopropylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid isobutylamide.
 101. The compound as defined in claim 1 which is 5-isopropylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid sec.-butylamide.
 102. The compound as defined in claim 1 which is 5-isopropylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid methylamide.
 103. The compound as defined in claim 1 which is 5-isopropylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 104. The compound as defined in claim 1 which is 5-(2-propenylsulfinyl)-1,3,4-thiadiazole-2-carboxylic acid methylamide.
 105. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid N-ethyl-N-butylamide.
 106. The compound as defined in claim 1 which is 5-isopropylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid propylamide.
 107. The compound as defined in claim 1 which is 5-isopropylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 108. The compound as defined in claim 1 which is 5-isopropylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid dimethylamide.
 109. The compound as defined in claim 1 which is 5-butylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid methylamide.
 110. The compound as defined in claim 1 which is 5-butylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 111. The compound as defined in claim 1 which is 5-butylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid propylamide.
 112. The compound as defined in claim 1 which is 5-butylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid (2-methoxyethyl)-amide.
 113. The compound as defined in claim 1 which is 5-butylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 114. The compound as defined in claim 1 which is 5-butylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid methylamide.
 115. The compound as defined in claim 1 which is 5-butylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 116. The compound as defined in claim 1 which is 5-butylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid propylamide.
 117. The compound as defined in claim 1 which is 5-butylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid (2-methoxyethyl)-amide.
 118. The compound as defined in claim 1 which is 5-butylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 119. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid N-butyl-N-methylamide.
 120. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid N-isobutyl-N-methylamide.
 121. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid N,N-diethylamide.
 122. The compound as defined in claim 1 which is 5-sec.-butylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid methylamide.
 123. The compound as defined in claim 1 which is 5-sec.-butylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 124. The compound as defined in claim 1 which is 5-cyclohexylsulfonyl-1,3,4-thiadiazole-2-carboxamide.
 125. The compound as defined in claim 1 which is 5-cyclohexylsulfonyl-1,3,4-thiadiazole-2-carbonitrile.
 126. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid N,N-dipropylamide.
 127. The compound as defined in claim 1 which is 5-sec. butylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid cyclopropylamide.
 128. The compound as defined in claim 1 which is 5-pentylsulfinyl-1,3,4-thiadiazole-2-carbonitrile.
 129. The compound as defined in claim 1 which is 5-hexylsulfinyl-1,3,4-thiadiazole-2-carbonitrile.
 130. The compound as defined in claim 1 which is 5-pentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid methylamide.
 131. The compound as defined in claim 1 which is 5-hexylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid methylamide.
 132. The compound as defined in claim 1 which is 5-cyclohexylsulfinyl-1,3,4-thiadiazole-2-carbonitrile.
 133. The compound as defined in claim 1 which is 5-sec. butylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid (2-methoxyethyl)-amide.
 134. The compound as defined in claim 1 which is 5-sec.-butylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid methylamide.
 135. The compound as defined in claim 1 which is 5-sec.-butylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 136. The compound as defined in claim 1 which is 5-pentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 137. The compound as defined in claim 1 which is 5-hexylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 138. The compound as defined in claim 1 which is 5-pentylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 139. The compound as defined in claim 1 which is 5-hexylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 140. The compound as defined in claim 1 which is 5-methylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid N,N-diethylamide.
 141. The compound as defined in claim 1 which is 5-sec.-butylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 142. The compound as defined in claim 1 which is 5-sec. butylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid cyclopropylamide.
 143. The compound as defined in claim 1 which is 5-pentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid propylamide.
 144. The compound as defined in claim 1 which is 5-pentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 145. The compound as defined in claim 1 which is 5-pentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid cyclopropylamide.
 146. The compound as defined in claim 1 which is 5-pentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid butylamide.
 147. The compound as defined in claim 1 which is 5-pentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid sec.-butylamide.
 148. The compound as defined in claim 1 which is 5-pentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid isobutylamide.
 149. The compound as defined in claim 1 which is 5-pentylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid propylamide.
 150. The compound as defined in claim 1 which is 5-pentylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 151. The compound as defined in claim 2 which is 5-pentylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid allylamide.
 152. The compound as defined in claim 1 which is 5-pentylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid cyclopropylamide.
 153. The compound as defined in claim 1 which is 5-pentylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid butylamide.
 154. The compound as defined in claim 1 which is 5-pentylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid sec.-butylamide.
 155. The compound as defined in claim 1 which is 5-pentylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid isobutylamide.
 156. The compound as defined in claim 1 which is 5-cyclopentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid methylamide.
 157. The compound as defined in claim 1 which is 5-cyclopentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 158. The compound as defined in claim 1 which is 5-sec.-butylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid (2-methoxyethyl)-amide.
 159. The compound as defined in claim 1 which is 5-sec.-butylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid (3-methoxypropyl)-amide.
 160. The compound as defined in claim 1 which is 5-cyclopentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid propylamide.
 161. The compound as defined in claim 1 which is 5-cyclopentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 162. The compound as defined in claim 1 which is 5-cyclopentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid cyclopropylamide.
 163. The compound as defined in claim 1 which is 5-cyclopentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid butylamide.
 164. The compound as defined in claim 1 which is 5-cyclopentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid dimethylamide.
 165. The compound as defined in claim 1 which is 5-pentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid dimethylamide.
 166. The compound as defined in claim 1 which is 5-pentylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid (3-methoxypropyl)-amide.
 167. The compound as defined in claim 1 which is 5-hexylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid propylamide.
 168. The compound as defined in claim 1 which is 5-hexylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 169. The compound as defined in claim 1 which is 5-hexylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid (2-methoxyethyl)-amide.
 170. The compound as defined in claim 1 which is 5-hexylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid (3-methoxypropyl)-amide.
 171. The compound as defined in claim 1 which is 5-cyclopentylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid methylamide.
 172. The compound as defined in claim 1 which is 5-cyclopentylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide.
 173. The compound as defined in claim 1 which is 5-methylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid N,N-diisopropylamide.
 174. The compound as defined in claim 1 which is 5-sec.-butylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid (3-methoxypropyl)-amide.
 175. The compound as defined in claim 1 which is 5-hexylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid propylamide.
 176. The compound as defined in claim 1 which is 5-hexylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid isopropylamide.
 177. The compound as defined in claim 1 which is 5-hexylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid (2-propenyl)-amide.
 178. The compound as defined in claim 1 which is 5-hexylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid cyclopropylamide.
 179. The compound as defined in claim 1 which is 5-hexylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid (2-methoxyethyl)-amide.
 180. The compound as defined in claim 1 which is 5-hexylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid cyclopropylamide.
 181. The compound as defined in claim 1 which is 5-hexylsulfinyl-1,3,4-thiadiazole-2-carboxylic acid (3-methoxypropyl)-amide.
 182. The compound as defined in claim 1 which is 5-ethylsulfonyl-1,3,4-thiadiazole-2-carboxylic acid ethylamide. 